文章目录
GitHub:https://github.com/AnJiaoDe/TabLayoutNiubility
CSDN:https://blog.csdn.net/confusing_awakening/article/details/107635695
该轮子特异功能如下：
使用方法
注意：该轮子适用于androidx中的ViewPager2和ViewPager
注意：如果轮子死活下载不下来，说明maven地址有毛病，你需要找到jitpack的官网首页，查看最新的官网地址
注意：记得去gayhub查看最新版本，最新版本最niubility
详细使用如下
Tab均分不滑动(ViewPager、ViewPager2均支持)
Tab滑动、 indicator蠕动、多布局(ViewPager、ViewPager2均支持)
根据item个数动态设置Tab均分还是滑动
Tab文字颜色渐变(ViewPager、ViewPager2均支持)
自定义Indicator如三角形(ViewPager、ViewPager2均支持)
ViewPager双层嵌套(建议不要使用ViewPager2进行双层嵌套，ViewPager2嵌套滑动冲突几乎无法处理，贼鸡儿坑)
仿微信主页Tab
千古BUG：Activity销毁重启，Fragment恢复问题
AndroidX ViewPager中的FragmentStatePagerAdapter存在的问题
AndroidX ViewPager2中的FragmentStateAdapter存在的问题
自定义fragment
自定义Fragment PageContainer 双层嵌套（ViewPager和ViewPager2均适用）
相关API
TabMediator
FragmentPageAdapter
TabAdapter
TabLayoutScroll、TabLayoutNoScroll、TabLayoutMulti、IndicatorLineView 、 IndicatorTriangleView
TabLayoutScroll和 indicator style设置
自定义indicator
实现原理剖析
说真的，这自定义控件还真不简单
涉及到的难点场景
搞清楚ViewPager监听的onPageSelected、onPageScrolled和onPageScrollStateChanged回调执行特点
自定义HorizontalRecyclerView实现TabLayout
源码如下
TabLayout的item宽度均分
RecyclerView的item刷新如何做到不闪烁
UML类图如下
面向接口编程（面向多态编程）的思想
欢迎联系、指正、批评
GitHub:https://github.com/AnJiaoDe/TabLayoutNiubility
CSDN:https://blog.csdn.net/confusing_awakening/article/details/107635695
该轮子特异功能如下：
Tab均分不滑动(ViewPager、ViewPager2均支持)
Tab滑动、 indicator蠕动、多布局(ViewPager、ViewPager2均支持)
根据item个数动态设置Tab均分还是滑动
Tab文字颜色渐变(ViewPager、ViewPager2均支持)
自定义Indicator如三角形(ViewPager、ViewPager2均支持)
ViewPager双层嵌套(建议不要使用ViewPager2进行双层嵌套，ViewPager2嵌套滑动冲突几乎无法处理，贼鸡儿坑)
仿微信主页Tab
自定义fragment
使用方法
注意：该轮子适用于androidx中的ViewPager2和ViewPager
1.工程目录下的build.gradle中添加代码：
注意：如果轮子死活下载不下来，说明maven地址有毛病，你需要找到jitpack的官网首页，查看最新的官网地址
allprojects {
repositories {
maven { url 'https://www.jitpack.io' }
}
}
2.直接在需要使用的模块的build.gradle中添加代码：
dependencies {
api 'com.github.AnJiaoDe:TabLayoutNiubility:V1.2.8'
}
注意：记得去gayhub查看最新版本，最新版本最niubility
3.如果你想使用ViewPager2,那么添加代码：
api 'androidx.viewpager2:viewpager2:1.0.0'//版本必须>=1.0.0
4.混淆已配置到库内部，无需做混淆配置
详细使用如下
Tab均分不滑动(ViewPager、ViewPager2均支持)
xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.cy.tablayoutniubility.TabLayoutNoScroll
android:id="@+id/tablayout"
android:layout_width="match_parent"
android:layout_height="40dp"
app:space_horizontal="0dp"
android:background="#fff">
<com.cy.tablayoutniubility.IndicatorLineView
android:layout_width="match_parent"
app:width_indicator_max="80dp"
app:width_indicator_selected="30dp"
android:layout_height="wrap_content" />
com.cy.tablayoutniubility.TabLayoutNoScroll>
<androidx.viewpager2.widget.ViewPager2
android:id="@+id/view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:overScrollMode="never" />
LinearLayout>
tab_item布局：
xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/tv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:textColor="#444444"
android:textSize="16sp" >
TextView>
JAVA代码：
ViewPager2 viewPager2 = findViewById(R.id.view_pager);
TabLayoutNoScroll tabLayoutLine = findViewById(R.id.tablayout);
// tabLayoutLine.setSpace_horizontal(0).setSpace_vertical(0);
FragPageAdapterVp2NoScroll<String> fragmentPageAdapter = new FragPageAdapterVp2NoScroll<String>(this) {
@Override
public Fragment createFragment(String bean, int position) {
return FragmentTab2.newInstance(FragmentTab2.TAB_NAME2, getList_bean().get(position));
}
@Override
public void bindDataToTab(TabNoScrollViewHolder holder, int position, String bean, boolean isSelected) {
TextView textView = holder.getView(R.id.tv);
if (isSelected) {
textView.setTextColor(0xffe45540);
textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD));
} else {
textView.setTextColor(0xff444444);
textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL));
}
textView.setText(bean);
}
@Override
public int getTabLayoutID(int position, String bean) {
return R.layout.item_tab_center;
}
};
TabAdapterNoScroll<String> tabAdapter = new TabMediatorVp2NoScroll<String>(tabLayoutLine, viewPager2).setAdapter(fragmentPageAdapter);
List<String> list = new ArrayList<>();
list.add("关注");
list.add("推荐");
list.add("上课");
list.add("抗疫");
fragmentPageAdapter.add(list);
tabAdapter.add(list);
Tab滑动、 indicator蠕动、多布局(ViewPager、ViewPager2均支持)
多布局：
@Override
public int getTabLayoutID(int position, String bean) {
if (position == 0) {
return R.layout.item_tab_msg;
}
return R.layout.item_tab;
}
xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.cy.tablayoutniubility.TabLayoutScroll
android:id="@+id/tablayout"
android:layout_width="match_parent"
android:layout_height="40dp"
android:background="#fff">
<com.cy.tablayoutniubility.IndicatorLineView
android:layout_width="match_parent"
android:layout_height="wrap_content" />
com.cy.tablayoutniubility.TabLayoutScroll>
<androidx.viewpager2.widget.ViewPager2
android:id="@+id/view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:overScrollMode="never" />
LinearLayout>
tab item布局：
xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="center"
android:textSize="16sp"
android:textColor="#444444"
android:id="@+id/tv">
TextView>
JAVA代码：
ViewPager2 viewPager2 = findViewById(R.id.view_pager);
TabLayoutScroll tabLayoutLine = findViewById(R.id.tablayout);
// tabLayoutLine.setSpace_horizontal(dpAdapt(20)).setSpace_vertical(dpAdapt(8));
FragPageAdapterVp2<String> fragmentPageAdapter = new FragPageAdapterVp2<String>(this) {
@Override
public Fragment createFragment(String bean, int position) {
return FragmentTab2.newInstance(FragmentTab2.TAB_NAME2, getList_bean().get(position));
}
@Override
public void bindDataToTab(TabViewHolder holder, int position, String bean, boolean isSelected) {
TextView textView = holder.getView(R.id.tv);
if (isSelected) {
textView.setTextColor(0xffe45540);
textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD));
} else {
textView.setTextColor(0xff444444);
textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL));
}
textView.setText(bean);
}
@Override
public int getTabLayoutID(int position, String bean) {
if (position == 0) {
return R.layout.item_tab_msg;
}
return R.layout.item_tab;
}
};
TabAdapter<String> tabAdapter = new TabMediatorVp2<String>(tabLayoutLine, viewPager2).setAdapter(fragmentPageAdapter);
List<String> list = new ArrayList<>();
list.add("关注");
list.add("推荐");
list.add("视频");
list.add("抗疫");
list.add("酷玩");
list.add("彩票");
list.add("漫画");
fragmentPageAdapter.add(list);
tabAdapter.add(list);
根据item个数动态设置Tab均分还是滑动
使用TabLayoutMulti
xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.cy.tablayoutniubility.TabLayoutMulti
android:id="@+id/tablayout"
android:layout_width="match_parent"
android:layout_height="40dp"
app:space_horizontal="0dp"
android:background="#fff">
<com.cy.tablayoutniubility.IndicatorLineView
android:layout_width="match_parent"
app:width_indicator_max="80dp"
app:width_indicator_selected="30dp"
android:layout_height="wrap_content" />
com.cy.tablayoutniubility.TabLayoutMulti>
<androidx.viewpager2.widget.ViewPager2
android:id="@+id/view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:overScrollMode="never" />
LinearLayout>
JAVA代码：
6) tabLayoutMulti.setScrollable(true); BaseFragPageAdapterVp2 fragmentPageAdapter; if (tabLayoutMulti.isScrollable()) { fragmentPageAdapter = new FragPageAdapterVp2
(this) { @Override public Fragment createFragment(String bean, int position) { return FragmentTab2.newInstance(FragmentTab2.TAB_NAME2, getList_bean().get(position)); } @Override public void bindDataToTab(TabViewHolder holder, int position, String bean, boolean isSelected) { TextView textView = holder.getView(R.id.tv); if (isSelected) { textView.setTextColor(0xffe45540); textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD)); } else { textView.setTextColor(0xff444444); textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL)); } textView.setText(bean); } @Override public int getTabLayoutID(int position, String bean) { return R.layout.item_tab_center; } }; }else { fragmentPageAdapter = new FragPageAdapterVp2NoScroll
(this) { @Override public Fragment createFragment(String bean, int position) { return FragmentTab2.newInstance(FragmentTab2.TAB_NAME2, getList_bean().get(position)); } @Override public void bindDataToTab(TabNoScrollViewHolder holder, int position, String bean, boolean isSelected) { LogUtils.log("bindDataToTab"); TextView textView = holder.getView(R.id.tv); if (isSelected) { textView.setTextColor(0xffe45540); textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD)); } else { textView.setTextColor(0xff444444); textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL)); } textView.setText(bean); } @Override public int getTabLayoutID(int position, String bean) { return R.layout.item_tab_center; } }; } ITabAdapter tabAdapter = new TabMediatorMulti
(tabLayoutMulti).setAdapter(viewPager2, fragmentPageAdapter); fragmentPageAdapter.add(list); tabAdapter.add(list); //或者 // if(tabLayoutMulti.isScrollable()){ // TabAdapter tabAdapt= (TabAdapter) tabAdapter.getAdapter(); // tabAdapt.add(list); // }else { // TabAdapterNoScroll tabAdapt= (TabAdapterNoScroll) tabAdapter.getAdapter(); // tabAdapt.add(list); // } ">
ViewPager2 viewPager2 = findViewById(R.id.view_pager); TabLayoutMulti tabLayoutMulti = findViewById(R.id.tablayout); // tabLayoutLine.setSpace_horizontal(0).setSpace_vertical(0); List<String> list = new ArrayList<>(); list.add("关注"); list.add("推荐"); list.add("上课"); list.add("抗疫"); list.add("文化"); // list.add("经济"); // list.add("幸福里"); //根据item个数设置是否需要滚动 if (list.size() > 6) tabLayoutMulti.setScrollable(true); BaseFragPageAdapterVp2 fragmentPageAdapter; if (tabLayoutMulti.isScrollable()) { fragmentPageAdapter = new FragPageAdapterVp2<String>(this) { @Override public Fragment createFragment(String bean, int position) { return FragmentTab2.newInstance(FragmentTab2.TAB_NAME2, getList_bean().get(position)); } @Override public void bindDataToTab(TabViewHolder holder, int position, String bean, boolean isSelected) { TextView textView = holder.getView(R.id.tv); if (isSelected) { textView.setTextColor(0xffe45540); textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD)); } else { textView.setTextColor(0xff444444); textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL)); } textView.setText(bean); } @Override public int getTabLayoutID(int position, String bean) { return R.layout.item_tab_center; } }; }else { fragmentPageAdapter = new FragPageAdapterVp2NoScroll<String>(this) { @Override public Fragment createFragment(String bean, int position) { return FragmentTab2.newInstance(FragmentTab2.TAB_NAME2, getList_bean().get(position)); } @Override public void bindDataToTab(TabNoScrollViewHolder holder, int position, String bean, boolean isSelected) { LogUtils.log("bindDataToTab"); TextView textView = holder.getView(R.id.tv); if (isSelected) { textView.setTextColor(0xffe45540); textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD)); } else { textView.setTextColor(0xff444444); textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL)); } textView.setText(bean); } @Override public int getTabLayoutID(int position, String bean) { return R.layout.item_tab_center; } }; } ITabAdapter tabAdapter = new TabMediatorMulti<String>(tabLayoutMulti).setAdapter(viewPager2, fragmentPageAdapter); fragmentPageAdapter.add(list); tabAdapter.add(list); //或者 // if(tabLayoutMulti.isScrollable()){ // TabAdapter tabAdapt= (TabAdapter) tabAdapter.getAdapter(); // tabAdapt.add(list); // }else { // TabAdapterNoScroll tabAdapt= (TabAdapterNoScroll) tabAdapter.getAdapter(); // tabAdapt.add(list); // }
Tab文字颜色渐变(ViewPager、ViewPager2均支持)
xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:layout_width="match_parent"
android:background="#fff"
android:layout_height="match_parent" >
<com.cy.tablayoutniubility.TabLayoutScroll
android:layout_width="match_parent"
android:background="#fff"
android:layout_height="40dp"
android:id="@+id/tablayout">
<com.cy.tablayoutniubility.IndicatorLineView
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
com.cy.tablayoutniubility.TabLayoutScroll>
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="#eee"/>
<androidx.viewpager2.widget.ViewPager2
android:id="@+id/view_pager"
android:overScrollMode="never"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
LinearLayout>
tab item布局：
xml version="1.0" encoding="utf-8"?>
<com.cy.tablayoutniubility.TabGradientTextView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/tv"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="center"
android:textSize="16sp"
app:textColorNormal="#ff444444"
app:textColorSelected="#ffe45540">
com.cy.tablayoutniubility.TabGradientTextView>
JAVA代码：
tabAdapter = new TabMediatorVp2
(tabLayoutLine, viewPager2).setAdapter(fragmentPageAdapter); List
list = new ArrayList<>(); list.add("关注"); list.add("推荐"); list.add("视频"); list.add("抗疫"); list.add("彩票"); list.add("漫画"); fragmentPageAdapter.add(list); tabAdapter.add(list); ">
ViewPager2 viewPager2= findViewById(R.id.view_pager); TabLayoutScroll tabLayoutLine= findViewById(R.id.tablayout); // tabLayoutLine.setSpace_horizontal(dpAdapt(20)).setSpace_vertical(dpAdapt(8)); FragPageAdapterVp2<String> fragmentPageAdapter = new FragPageAdapterVp2<String>(this) { @Override public Fragment createFragment(String bean, int position) { return FragmentTab2.newInstance(FragmentTab2.TAB_NAME2, getList_bean().get(position)); } @Override public void bindDataToTab(TabViewHolder holder, int position, String bean, boolean isSelected) { TabGradientTextView textView = holder.getView(R.id.tv); if (isSelected) { textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD)); //因为 public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { //positionOffset没有为1的时候 //必须 textView.setProgress(1); } else { textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL)); //因为快速滑动时， public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { //positionOffset不会出现0 //必须 textView.setProgress(0); } textView.setText(bean); } @Override public int getTabLayoutID(int position, String bean) { return R.layout.item_tab_gradient; } @Override public void onTabScrolled(TabViewHolder holderCurrent, int positionCurrent, boolean fromLeft2RightCurrent, float positionOffsetCurrent, TabViewHolder holder2, int position2, boolean fromLeft2Right2, float positionOffset2) { super.onTabScrolled(holderCurrent, positionCurrent, fromLeft2RightCurrent, positionOffsetCurrent, holder2, position2, fromLeft2Right2, positionOffset2); TabGradientTextView textViewCurrent = holderCurrent.getView(R.id.tv); TabGradientTextView textView2= holder2.getView(R.id.tv); LogUtils.log("onTabScrolled"); textViewCurrent.setDirection(fromLeft2RightCurrent?TabGradientTextView.DIRECTION_FROM_LEFT:TabGradientTextView.DIRECTION_FROM_RIGHT) .setProgress(positionOffsetCurrent); textView2.setDirection(fromLeft2Right2?TabGradientTextView.DIRECTION_FROM_LEFT:TabGradientTextView.DIRECTION_FROM_RIGHT) .setProgress(positionOffset2); } }; TabAdapter<String> tabAdapter = new TabMediatorVp2<String>(tabLayoutLine, viewPager2).setAdapter(fragmentPageAdapter); List<String> list = new ArrayList<>(); list.add("关注"); list.add("推荐"); list.add("视频"); list.add("抗疫"); list.add("彩票"); list.add("漫画"); fragmentPageAdapter.add(list); tabAdapter.add(list);
自定义Indicator如三角形(ViewPager、ViewPager2均支持)
可以在布局或者代码中设置三角形的选中宽度和最大宽度，使三角形宽度不改变
xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:layout_width="match_parent"
android:background="#fff"
android:layout_height="match_parent" >
<com.cy.tablayoutniubility.TabLayoutScroll
android:layout_width="match_parent"
android:background="#fff"
android:layout_height="40dp"
android:id="@+id/tablayout">
<com.cy.tablayoutniubility.IndicatorTriangleView
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
com.cy.tablayoutniubility.TabLayoutScroll>
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="#eee"/>
<androidx.viewpager2.widget.ViewPager2
android:id="@+id/view_pager"
android:overScrollMode="never"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
LinearLayout>
tab item布局：
xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="center"
android:textSize="16sp"
android:textColor="#444444"
android:id="@+id/tv">
TextView>
JAVA代码：
ViewPager2 viewPager2= findViewById(R.id.view_pager);
TabLayoutScroll tabLayoutNiubility= findViewById(R.id.tablayout);
// tabLayoutTriangle.setSpace_horizontal(dpAdapt(20)).setSpace_vertical(dpAdapt(8));
FragPageAdapterVp2<String> fragmentPageAdapter = new FragPageAdapterVp2<String>(this) {
@Override
public Fragment createFragment(String bean, int position) {
return FragmentTab2.newInstance(FragmentTab2.TAB_NAME2, getList_bean().get(position));
}
@Override
public void bindDataToTab(TabViewHolder holder, int position, String bean, boolean isSelected) {
TextView textView = holder.getView(R.id.tv);
if (isSelected) {
textView.setTextColor(0xffe45540);
textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD));
} else {
textView.setTextColor(0xff444444);
textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL));
}
textView.setText(bean);
}
@Override
public int getTabLayoutID(int position, String bean) {
return R.layout.item_tab;
}
};
TabAdapter<String> tabAdapter = new TabMediatorVp2<String>(tabLayoutNiubility, viewPager2).setAdapter(fragmentPageAdapter);
List<String> list = new ArrayList<>();
list.add("关注");
list.add("推荐");
list.add("彩票");
list.add("漫画");
fragmentPageAdapter.add(list);
tabAdapter.add(list);
ViewPager双层嵌套(建议不要使用ViewPager2进行双层嵌套，ViewPager2嵌套滑动冲突几乎无法处理，贼鸡儿坑)
xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.cy.tablayoutniubility.TabLayoutScroll
android:id="@+id/tablayout"
android:layout_width="match_parent"
android:layout_height="40dp"
android:background="#fff">
<com.cy.tablayoutniubility.IndicatorLineView
android:layout_width="match_parent"
android:layout_height="wrap_content" />
com.cy.tablayoutniubility.TabLayoutScroll>
<androidx.viewpager.widget.ViewPager
android:id="@+id/view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:overScrollMode="never" />
LinearLayout>
activity代码：
ViewPager viewPager= findViewById(R.id.view_pager);
TabLayoutScroll tabLayoutLine= findViewById(R.id.tablayout);
// tabLayoutLine.setSpace_horizontal(dpAdapt(20)).setSpace_vertical(dpAdapt(8));
FragPageAdapterVp<String> fragmentPageAdapter = new FragPageAdapterVp<String>(getSupportFragmentManager(),
FragmentStatePagerAdapter.BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT) {
@Override
public Fragment createFragment(String bean, int position) {
return FragmentTab1.newInstance(FragmentTab1.TAB_NAME1, getList_bean().get(position));
}
@Override
public void bindDataToTab(TabViewHolder holder, int position, String bean, boolean isSelected) {
TextView textView = holder.getView(R.id.tv);
if (isSelected) {
textView.setTextColor(0xffe45540);
textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD));
} else {
textView.setTextColor(0xff444444);
textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL));
}
textView.setText(bean);
}
@Override
public int getTabLayoutID(int position, String bean) {
if (position == 0) {
return R.layout.item_tab_msg;
}
return R.layout.item_tab;
}
};
TabAdapter<String> tabAdapter = new TabMediatorVp<String>(tabLayoutLine, viewPager).setAdapter(fragmentPageAdapter);
List<String> list = new ArrayList<>();
list.add("关注");
list.add("推荐");
list.add("酷玩");
list.add("彩票");
list.add("漫画");
fragmentPageAdapter.add(list);
tabAdapter.add(list);
Fragment代码：
tabAdapter = new TabMediatorVp
(tabLayoutLine, viewPager).setAdapter(fragmentPageAdapter); if (getArguments() != null) { String tab_name1 = getArguments().getString(TAB_NAME1); List
list = new ArrayList<>(); list.add(tab_name1 + "0"); list.add(tab_name1 + "1"); list.add(tab_name1 + "2"); list.add(tab_name1 + "3"); list.add(tab_name1 + "4"); list.add(tab_name1 + "5"); list.add(tab_name1 + "6"); list.add(tab_name1 + "7"); list.add(tab_name1 + "8"); list.add(tab_name1 + "9"); list.add(tab_name1 + "10"); list.add(tab_name1 + "11"); list.add(tab_name1 + "12"); list.add(tab_name1 + "13"); fragmentPageAdapter.add(list); tabAdapter.add(list); } ">
viewPager = view.findViewById(R.id.view_pager); tabLayoutLine = view.findViewById(R.id.tablayout); FragPageAdapterVp<String> fragmentPageAdapter = new FragPageAdapterVp<String>(getChildFragmentManager(), FragmentStatePagerAdapter.BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT) { @Override public Fragment createFragment(String bean, int position) { return FragmentTab2.newInstance(FragmentTab2.TAB_NAME2, getList_bean().get(position)); } @Override public void bindDataToTab(TabViewHolder holder, int position, String bean, boolean isSelected) { TextView textView = holder.getView(R.id.tv); if (isSelected) { LogUtils.log("bindDataToTabisSelected",position); textView.setTextColor(0xffe45540); textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD)); } else { LogUtils.log("bindDataToTab",position); textView.setTextColor(0xff444444); textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL)); } textView.setText(bean); } @Override public int getTabLayoutID(int position, String bean) { return R.layout.item_tab; } }; TabAdapter<String> tabAdapter = new TabMediatorVp<String>(tabLayoutLine, viewPager).setAdapter(fragmentPageAdapter); if (getArguments() != null) { String tab_name1 = getArguments().getString(TAB_NAME1); List<String> list = new ArrayList<>(); list.add(tab_name1 + "0"); list.add(tab_name1 + "1"); list.add(tab_name1 + "2"); list.add(tab_name1 + "3"); list.add(tab_name1 + "4"); list.add(tab_name1 + "5"); list.add(tab_name1 + "6"); list.add(tab_name1 + "7"); list.add(tab_name1 + "8"); list.add(tab_name1 + "9"); list.add(tab_name1 + "10"); list.add(tab_name1 + "11"); list.add(tab_name1 + "12"); list.add(tab_name1 + "13"); fragmentPageAdapter.add(list); tabAdapter.add(list); }
仿微信主页Tab
activity布局：
xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<androidx.viewpager2.widget.ViewPager2
android:id="@+id/view_pager"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:overScrollMode="never" />
<com.cy.tablayoutniubility.TabLayoutNoScroll
android:id="@+id/tablayout"
android:layout_width="match_parent"
android:layout_height="60dp"
android:background="#fff">
<com.cy.tablayoutniubility.IndicatorNullView
android:layout_width="match_parent"
android:layout_height="wrap_content" />
com.cy.tablayoutniubility.TabLayoutNoScroll>
LinearLayout>
item布局：
xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical">
<ImageView
android:id="@+id/iv"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scaleType="centerInside" />
<TextView
android:id="@+id/tv"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="4dp"
android:gravity="center"
android:textSize="12sp">TextView>
LinearLayout>
JAVA代码：
ViewPager2 viewPager2= findViewById(R.id.view_pager);
TabLayoutNoScroll tabLayoutNoScroll= findViewById(R.id.tablayout);
FragPageAdapterVp2NoScroll<TabBean> fragmentPageAdapter = new FragPageAdapterVp2NoScroll<TabBean>(this) {
@Override
public Fragment createFragment(TabBean bean, int position) {
return FragmentTab2.newInstance(FragmentTab2.TAB_NAME2, getList_bean().get(position).getText());
}
@Override
public void bindDataToTab(TabNoScrollViewHolder holder, int position, TabBean bean, boolean isSelected) {
TextView textView = holder.getView(R.id.tv);
if (isSelected) {
textView.setTextColor(0xff00ff00);
holder.setImageResource(R.id.iv,bean.getResID_selected());
} else {
textView.setTextColor(0xff444444);
holder.setImageResource(R.id.iv,bean.getResID_normal());
}
textView.setText(bean.getText());
}
@Override
public int getTabLayoutID(int position, TabBean bean) {
if (position == 2) {
return R.layout.item_tab_main_circle;
}
return R.layout.item_tab_main;
}
};
TabAdapterNoScroll<TabBean> tabAdapter = new TabMediatorVp2NoScroll<TabBean>(tabLayoutNoScroll, viewPager2).setAdapter(fragmentPageAdapter);
List<TabBean> list = new ArrayList<>();
list.add(new TabBean("消息",R.drawable.msg,R.drawable.msg_selected));
list.add(new TabBean("通讯录",R.drawable.friends,R.drawable.friends_selected));
list.add(new TabBean("朋友圈",R.drawable.circle,R.drawable.circle_selected));
list.add(new TabBean("我",R.drawable.my,R.drawable.my_selected));
fragmentPageAdapter.add(list);
tabAdapter.add(list);
千古BUG：Activity销毁重启，Fragment恢复问题
当用户修改了手机字体大小，语言等，Activity会被销毁并重启，其中的Fragment会在Activity的 super.onCreate(savedInstanceState);中恢复，这样就出了个严重的BUG：Activity被回收，Activity持有的所有数据和对象均被回收，假如Fragment持有了Activity的某些数据或者对象，在Acitivty尚未来得及初始化这些数据和对象的时候，去恢复Fragment,这时候必然报空指针异常，这种现象尤其是在ViewPager和Fragment双层嵌套使用时尤为造孽。
虽然有很直接的办法：就是判断NULL，但这样写代码未免极其不爽，而且还不保证绝对不出问题。
也有人用这种办法：
在onSaveInstanceState中做手脚，然而小编试了，并不灵，而且小编不推荐这样做，因为这样做，代码肯定不健壮。
FragmentActivity重启时Fragment状态异常的问题解决办法
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
AndroidX ViewPager中的FragmentStatePagerAdapter存在的问题
@Override
public Object instantiateItem(@NonNull ViewGroup container, int position) {
// If we already have this item instantiated, there is nothing
// to do. This can happen when we are restoring the entire pager
// from its saved state, where the fragment manager has already
// taken care of restoring the fragments we previously had instantiated.
if (mFragments.size() > position) {
Fragment f = mFragments.get(position);
if (f != null) {
return f;
}
}
if (mCurTransaction == null) {
mCurTransaction = mFragmentManager.beginTransaction();
}
Fragment fragment = getItem(position);
if (DEBUG) Log.v(TAG, "Adding item #" + position + ": f=" + fragment);
if (mSavedState.size() > position) {
Fragment.SavedState fss = mSavedState.get(position);
if (fss != null) {
fragment.setInitialSavedState(fss);
}
}
while (mFragments.size() <= position) {
mFragments.add(null);
}
fragment.setMenuVisibility(false);
if (mBehavior == BEHAVIOR_SET_USER_VISIBLE_HINT) {
fragment.setUserVisibleHint(false);
}
mFragments.set(position, fragment);
mCurTransaction.add(container.getId(), fragment);
if (mBehavior == BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT) {
mCurTransaction.setMaxLifecycle(fragment, Lifecycle.State.STARTED);
}
return fragment;
}
看到一处关键代码：
if (mFragments.size() > position) {
Fragment f = mFragments.get(position);
if (f != null) {
return f;
}
}
Fragment被缓存起来了，虽说节约内存，但是也容易出现身体不适，因为可能开发过程中，重新设置了adapter或者多种原因，这时，我们不希望缓存fragment了。
所以小编开发的轮子中，把这段使用缓存的代码删除了。
AndroidX ViewPager2中的FragmentStateAdapter存在的问题
private void ensureFragment(int position) {
long itemId = getItemId(position);
// if (!mFragments.containsKey(itemId)) {
// TODO(133419201): check if a Fragment provided here is a new Fragment
Fragment newFragment = createFragment(position);
newFragment.setInitialSavedState(mSavedStates.get(itemId));
mFragments.put(itemId, newFragment);
// }
}
可以看到和Androidx中的ViewPager的FragmentStatePagerAdapter一样缓存了Fragment, 小编在轮子中也把这段使用缓存的代码删除了。
自定义fragment
小编有超强的代码洁癖，所以不喜欢用一堆代码去解决API的某些身体不适，干脆自己自定义fragment，
做了基本的生命周期控制，但是生命周期肯定不如Fragment的强大，不过依然能满足基本需求，特别适用于ViewPgaer和Fragmnt双层嵌套使用的时候。
public abstract class PageContainer {
protected View view;
protected Context context;
private PageContainerChildManager pageContainerChildManager=new PageContainerChildManager();
private PageContainer pageContainerParent;
public PageContainer(PageContainer pageContainerParent) {
this.pageContainerParent = pageContainerParent;
}
public Context getContext() {
return context;
}
public View getView() {
return view;
}
public abstract View onCreateView(LayoutInflater layoutInflater, ViewGroup container);
public void onResume(boolean isFirstResume){}
public void onStop(){}
public void onDestroyView(){}
public final PageContainerChildManager getPageContainerChildManager() {
return pageContainerChildManager;
}
public final PageContainer getPageContainerParent() {
return pageContainerParent;
}
}
自定义Fragment PageContainer 双层嵌套（ViewPager和ViewPager2均适用）
tabAdapter = new TabMediatorVp
(tabLayoutLine, viewPager).setAdapter(containerPageAdapterVp); List
list = new ArrayList<>(); list.add("关注"); list.add("推荐"); list.add("视频"); list.add("漫画"); containerPageAdapterVp.add(list); tabAdapter.add(list); ">
ViewPager viewPager = findViewById(R.id.view_pager); TabLayoutScroll tabLayoutLine = findViewById(R.id.tablayout); // tabLayoutLine.setSpace_horizontal(dpAdapt(20)).setSpace_vertical(dpAdapt(8)); ContainerPageAdapterVp<String> containerPageAdapterVp = new ContainerPageAdapterVp<String>(viewPager) { @Override public PageContainer onCreatePageContainer(ViewGroup container, int position, String bean) { LogUtils.log("onCreatePageContainer", position); //该PageContainer属于第一层ViewPager,它的父PageContainer传null即可 return new PageContainerTab1(null, bean); } @Override public void bindDataToTab(TabViewHolder holder, int position, String bean, boolean isSelected) { LogUtils.log("createFragmentbindDataToTab", position); TextView textView = holder.getView(R.id.tv); if (isSelected) { textView.setTextColor(0xffe45540); textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD)); } else { textView.setTextColor(0xff444444); textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL)); } textView.setText(bean); } @Override public int getTabLayoutID(int position, String bean) { if (position == 0) { return R.layout.item_tab_msg; } return R.layout.item_tab; } }; TabAdapter<String> tabAdapter = new TabMediatorVp<String>(tabLayoutLine, viewPager).setAdapter(containerPageAdapterVp); List<String> list = new ArrayList<>(); list.add("关注"); list.add("推荐"); list.add("视频"); list.add("漫画"); containerPageAdapterVp.add(list); tabAdapter.add(list);
PageContainerTab1 代码：
containerPageAdapterVp = new ContainerPageAdapterVp
(viewPager) { @Override public PageContainer onCreatePageContainer(ViewGroup container, int position, String bean) { LogUtils.log("onCreatePageContainer", position); //该PageContainer属于第2层ViewPager,它的父PageContainer传PageContainerTab1.this即可 return new PageContainerTab2(PageContainerTab1.this, bean); } @Override public void bindDataToTab(TabViewHolder holder, int position, String bean, boolean isSelected) { TextView textView = holder.getView(R.id.tv); if (isSelected) { textView.setTextColor(0xffe45540); textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD)); } else { textView.setTextColor(0xff444444); textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL)); } textView.setText(bean); } @Override public int getTabLayoutID(int position, String bean) { return R.layout.item_tab; } }; TabAdapter
tabAdapter = new TabMediatorVp
(tabLayoutLine, viewPager).setAdapter(containerPageAdapterVp); List
list = new ArrayList<>(); if (bean.equals("关注")) { list.add(bean + "0"); list.add(bean + "1"); } else if (bean.equals("推荐")) { list.add(bean + "0"); } else { list.add(bean + "0"); list.add(bean + "1"); list.add(bean + "2"); list.add(bean + "3"); list.add(bean + "4"); list.add(bean + "5"); list.add(bean + "6"); list.add(bean + "7"); list.add(bean + "8"); list.add(bean + "9"); list.add(bean + "10"); list.add(bean + "11"); list.add(bean + "12"); list.add(bean + "13"); } containerPageAdapterVp.add(list); tabAdapter.add(list); return view; } @Override public void onResume(boolean isFirstResume) { super.onResume(isFirstResume); LogUtils.log("onResumetab1", bean + isFirstResume); } @Override public void onStop() { super.onStop(); LogUtils.log("onStop", bean); } @Override public void onDestroyView() { super.onDestroyView(); LogUtils.log("onDestroyView", bean); } } ">
public class PageContainerTab1 extends PageContainer { private String bean; public PageContainerTab1(PageContainer pageContainerParent, String bean) { super(pageContainerParent); this.bean = bean; } @Override public View onCreateView(LayoutInflater layoutInflater, ViewGroup container) { view = (ViewGroup) layoutInflater.inflate(R.layout.fragment_tab1, container, false); LogUtils.log("onCreateView"); ViewPager viewPager = view.findViewById(R.id.view_pager); TabLayoutScroll tabLayoutLine = view.findViewById(R.id.tablayout); ContainerPageAdapterVp<String> containerPageAdapterVp = new ContainerPageAdapterVp<String>(viewPager) { @Override public PageContainer onCreatePageContainer(ViewGroup container, int position, String bean) { LogUtils.log("onCreatePageContainer", position); //该PageContainer属于第2层ViewPager,它的父PageContainer传PageContainerTab1.this即可 return new PageContainerTab2(PageContainerTab1.this, bean); } @Override public void bindDataToTab(TabViewHolder holder, int position, String bean, boolean isSelected) { TextView textView = holder.getView(R.id.tv); if (isSelected) { textView.setTextColor(0xffe45540); textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD)); } else { textView.setTextColor(0xff444444); textView.setTypeface(Typeface.defaultFromStyle(Typeface.NORMAL)); } textView.setText(bean); } @Override public int getTabLayoutID(int position, String bean) { return R.layout.item_tab; } }; TabAdapter<String> tabAdapter = new TabMediatorVp<String>(tabLayoutLine, viewPager).setAdapter(containerPageAdapterVp); List<String> list = new ArrayList<>(); if (bean.equals("关注")) { list.add(bean + "0"); list.add(bean + "1"); } else if (bean.equals("推荐")) { list.add(bean + "0"); } else { list.add(bean + "0"); list.add(bean + "1"); list.add(bean + "2"); list.add(bean + "3"); list.add(bean + "4"); list.add(bean + "5"); list.add(bean + "6"); list.add(bean + "7"); list.add(bean + "8"); list.add(bean + "9"); list.add(bean + "10"); list.add(bean + "11"); list.add(bean + "12"); list.add(bean + "13"); } containerPageAdapterVp.add(list); tabAdapter.add(list); return view; } @Override public void onResume(boolean isFirstResume) { super.onResume(isFirstResume); LogUtils.log("onResumetab1", bean + isFirstResume); } @Override public void onStop() { super.onStop(); LogUtils.log("onStop", bean); } @Override public void onDestroyView() { super.onDestroyView(); LogUtils.log("onDestroyView", bean); } }
PageContainerTab2 代码：
public class PageContainerTab2 extends PageContainer {
private View view;
private String bean;
public PageContainerTab2(PageContainer pageContainerParent,String bean) {
super(pageContainerParent);
this.bean = bean;
}
@Override
public View onCreateView(LayoutInflater layoutInflater, ViewGroup container) {
view=layoutInflater.inflate(R.layout.fragment_tab2, container, false);
LogUtils.log("onCreateView",bean);
TextView textView = view.findViewById(R.id.tv);
textView.setText(bean);
return view;
}
@Override
public void onResume(boolean isFirstResume) {
super.onResume(isFirstResume);
LogUtils.log("onResumetab2",bean+isFirstResume);
}
@Override
public void onStop() {
super.onStop();
LogUtils.log("onStop",bean);
}
@Override
public void onDestroyView() {
super.onDestroyView();
LogUtils.log("onDestroyViewPageContainerTab2",bean);
}
}
相关API
TabMediator
TabMediatorVp
TabMediatorVp2
TabMediatorVp2NoScroll(不可滚动)
TabMediatorVpNoScroll(不可滚动)
TabMediatorMulti(可用于ViewPager和ViewPager2,可根据item个数动态设置是否滚动)
FragmentPageAdapter
拥有一系列add、remove函数
FragmentPageAdapterVp2（Tab可滑动，ViewPager2使用）
FragmentPageAdapterVp（Tab可滑动，ViewPager使用）
FragmentPageAdapterVp2NoScroll（Tab不可滑动，ViewPager2使用）
FragmentPageAdapterVpNoScroll（Tab不可滑动，ViewPager使用）
TabAdapter
TabAdapter(Tab的Adapter，继承自RecyclerView的Adapter) 拥有一系列add、remove函数
TabAdapterNoScroll(Tab的Adapter，不能滚动)
TabLayoutScroll、TabLayoutNoScroll、TabLayoutMulti、IndicatorLineView 、 IndicatorTriangleView
TabLayoutScroll是可滚动tab,TabLayoutNoScroll是不可滚动tab,里面需要嵌套indicatorview,可以选择IndicatorLineView线条indicator、IndicatorTriangleView三角形indicator, TabLayoutMulti用于需要根据item个数动态设置是否滚动
<com.cy.tablayoutniubility.TabLayoutNiubility
android:id="@+id/tablayout"
android:layout_width="match_parent"
android:layout_height="40dp"
android:background="#fff">
<com.cy.tablayoutniubility.IndicatorLineView
android:layout_width="match_parent"
android:layout_height="wrap_content" />
com.cy.tablayoutniubility.TabLayoutNiubility>
TabLayoutScroll和 indicator style设置
TabLayoutNiubility可设置space
indicator可设置颜色、选中长度、最大长度、高度、radius等
可在布局中使用 比如：
"><com.cy.tablayoutniubility.IndicatorLineView android:layout_width="match_parent" app:width_indicator_max="80dp" app:width_indicator_selected="30dp" android:layout_height="wrap_content" />
xml version="1.0" encoding="utf-8"?>
<resources>
<attr name="height_indicator" format="dimension|reference" />
<attr name="width_indicator_selected" format="dimension|reference"/>
<attr name="width_indicator_max" format="dimension|reference"/>
<attr name="color_indicator" format="color|reference"/>
<declare-styleable name="TabGradientTextView">
<attr name="textColorNormal" format="color|reference" />
<attr name="textColorSelected" format="color|reference"/>
declare-styleable>
<declare-styleable name="TabLayoutNiubility">
<attr name="space_vertical" format="dimension|reference"/>
<attr name="space_horizontal" format="dimension|reference"/>
declare-styleable>
<declare-styleable name="IndicatorLineView">
<attr name="height_indicator" />
<attr name="width_indicator_selected"/>
<attr name="width_indicator_max"/>
<attr name="radius_indicator" format="dimension|reference"/>
<attr name="color_indicator" />
declare-styleable>
<declare-styleable name="IndicatorTriangleView">
<attr name="height_indicator" />
<attr name="width_indicator_selected"/>
<attr name="width_indicator_max"/>
<attr name="color_indicator" />
declare-styleable>
resources>
可在代码中使用 比如：
tabLayoutScroll.getIndicatorView().getIndicator().setColor_indicator();
/**
* 设置indicator进度
* @param progress
* @return
*/
public Indicator setProgress(int progress) {
this.progress = progress;
viewIndicator.invalidate();
return this;
}
public int getProgress() {
return progress;
}
public int getWidth_indicator_max() {
return width_indicator_max;
}
/**
* 设置indicator最大长度
* @param width_indicator_max
* @return
*/
public Indicator setWidth_indicator_max(int width_indicator_max) {
this.width_indicator_max = width_indicator_max;
return this;
}
/**
* 设置indicator颜色
* @param color_indicator
* @return
*/
public Indicator setColor_indicator(int color_indicator) {
paint_indicator.setColor(color_indicator);
return this;
}
/**
* 设置indicator高度
* @param height_indicator
* @return
*/
public Indicator setHeight_indicator(int height_indicator) {
this.height_indicator = height_indicator;
return this;
}
public int getHeight_indicator() {
return height_indicator;
}
public Paint getPaint_indicator() {
return paint_indicator;
}
/**
* 设置indicator选中时的长度
* @param width_indicator_selected
* @return
*/
public Indicator setWidth_indicator_selected(int width_indicator_selected) {
this.width_indicator_selected = width_indicator_selected;
return this;
}
public int getWidth_indicator_selected() {
return width_indicator_selected;
}
public int getWidth_indicator() {
return width_indicator;
}
/**
* 设置indicator当前长度
* @param width_indicator
* @return
*/
public Indicator setWidth_indicator(int width_indicator) {
this.width_indicator = Math.min(width_indicator_max, width_indicator);
return this;
}
自定义indicator
1.实现IIndicatorView 接口 2.创建Indicator 对象、设置基本默认参数 3.实现draw方法，根据progress和width_indicator绘制自己想要的样式
比如库里提供的IndicatorTriangleView
public class IndicatorTriangleView extends View implements IIndicatorView {
private Path path;
private Indicator indicator;
private int height;
public IndicatorTriangleView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
indicator=new Indicator(this);
//实例化路径
path = new Path();
indicator=new Indicator(this);
TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.IndicatorTriangleView);
indicator.setWidth_indicator_selected(typedArray.getDimensionPixelSize(R.styleable.IndicatorTriangleView_width_indicator_selected, ScreenUtils.dpAdapt(context,12)));
indicator.setWidth_indicator_max(typedArray.getDimensionPixelSize(R.styleable.IndicatorTriangleView_width_indicator_max, ScreenUtils.dpAdapt(context,48)));
indicator.setHeight_indicator(typedArray.getDimensionPixelSize(R.styleable.IndicatorTriangleView_height_indicator, ScreenUtils.dpAdapt(context,6)));
indicator.setColor_indicator(typedArray.getColor(R.styleable.IndicatorTriangleView_color_indicator, 0xffe45540));
indicator.setWidth_indicator(ScreenUtils.dpAdapt(context,30));
typedArray.recycle();
}
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
height=getHeight();
}
@Override
public <T extends View> T getView() {
return (T) this;
}
@Override
public Indicator getIndicator() {
return indicator;
}
@Override
protected void onDraw(Canvas canvas) {
path.reset();
path.moveTo(indicator.getProgress(), height);// 此点为多边形的起点
path.lineTo(indicator.getProgress() + indicator.getWidth_indicator() * 1f / 2, height - indicator.getHeight_indicator());
path.lineTo(indicator.getProgress() + indicator.getWidth_indicator(), height);
path.close(); // 使这些点构成封闭的多边形
indicator.getPaint_indicator().setStyle(Paint.Style.FILL);
canvas.drawPath(path, indicator.getPaint_indicator());
}
}
实现原理剖析
说真的，这自定义控件还真不简单
涉及到的难点场景
搞清楚ViewPager监听的onPageSelected、onPageScrolled和onPageScrollStateChanged回调执行特点
/**
* This method will be invoked when the current page is scrolled, either as part
* of a programmatically initiated smooth scroll or a user initiated touch scroll.
*
* @param position Position index of the first page currently being displayed.
* Page position+1 will be visible if positionOffset is nonzero.
* @param positionOffset Value from [0, 1) indicating the offset from the page at position.
* @param positionOffsetPixels Value in pixels indicating the offset from position.
*/
public void onPageScrolled(int position, float positionOffset,
@Px int positionOffsetPixels) {
}
/**
* This method will be invoked when a new page becomes selected. Animation is not
* necessarily complete.
*
* @param position Position index of the new selected page.
*/
public void onPageSelected(int position) {
}
/**
* Called when the scroll state changes. Useful for discovering when the user begins
* dragging, when a fake drag is started, when the pager is automatically settling to the
* current page, or when it is fully stopped/idle. {@code state} can be one of {@link
* #SCROLL_STATE_IDLE}, {@link #SCROLL_STATE_DRAGGING} or {@link #SCROLL_STATE_SETTLING}.
*/
public void onPageScrollStateChanged(@ScrollState int state) {
}
首次进入viewPager,回调如下：
onPageSelected: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
手指向左拖动，viewapger从index切换到第index+1,回调如下：
可以发现当手指松开，ViewPager从SCROLL_STATE_DRAGGING到达SCROLL_STATE_SETTLING（自动滚动状态），onPageSelected先执行，onPageScrolled position从index 慢慢到index+1
LOG_E: ----------------------------------->>>>onPageScrollStateChangedSCROLL_STATE_DRAGGING
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
LOG_E: ----------------------------------->>>>onPageScrollStateChangedSCROLL_STATE_SETTLING
onPageSelected: ----------------------------------->>>>1
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>1
LOG_E: ----------------------------------->>>>onPageScrollStateChangedSCROLL_STATE_IDLE
手指向右拖动，viewapger从index切换到第index-1,回调如下：
onPageScrolled: ----------------------------------->>>>1
LOG_E: ----------------------------------->>>>onPageScrollStateChangedSCROLL_STATE_IDLE
LOG_E: ----------------------------------->>>>onPageScrollStateChangedSCROLL_STATE_DRAGGING
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
LOG_E: ----------------------------------->>>>onPageScrollStateChangedSCROLL_STATE_SETTLING
onPageSelected: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
onPageScrolled: ----------------------------------->>>>0
LOG_E: ----------------------------------->>>>onPageScrollStateChangedSCROLL_STATE_IDLE
可以发现当手指开始拖动，onPageScrolled position从index 直接变成index-1, 当手指松开，ViewPager从SCROLL_STATE_DRAGGING到达SCROLL_STATE_SETTLING（自动滚动状态），onPageSelected执行，onPageScrolled position不再改变，直到SCROLL_STATE_IDLE（自动滚动停止）
总结：onPageSelected先执行（粗略来说），手指向左拖动,onPageScrolled position是当前item的position+1,手指向右拖动,onPageScrolled position是当前item的position-1,搞懂这点是关键。
自定义HorizontalRecyclerView实现TabLayout
之所以选择RecyclerView做tabLayout，是因为RecyclerView最适用于多item的布局，不仅因为它有缓存的功能、还因为使用起来极其方便简单，个人觉得，android里recyclerView的设计是超级奶思的。
因为TabLayout需要根据ViewPager的滑动来滑动，但RecyclerView的scrollTo函数是空的，没有任何作用，这样滑动控制就会变得困难。不过我们可以override，自己实现它，通过scrollBy函数滑动，设置滑动监听事件，记录偏移量offsetX，这样，我们就可以做到scrollTo是有作用的。
public class HorizontalRecyclerView extends RecyclerView {
private LinearItemDecoration linearItemDecoration;
//永远<=0
private int offsetX = 0;
public HorizontalRecyclerView(Context context) {
this(context, null);
}
public HorizontalRecyclerView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
addOnScrollListener(new OnScrollListener() {
@Override
public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
offsetX -= dx;
}
});
SimpleItemAnimator simpleItemAnimator = (SimpleItemAnimator) getItemAnimator();
if (simpleItemAnimator != null) simpleItemAnimator.setSupportsChangeAnimations(false);
}
/**
* x为正，表示手指往左滑,x为负，表示手指往右滑
*
* @param x
* @param y
*/
@Override
public void scrollBy(int x, int y) {
super.scrollBy(x, y);
}
/**
* x<=0
* 比如 x=0,表示滑动到RecyclerView最左边，完全显示第一个item,
* 比如 x=-100,表示RecyclerView左边100像素的界面被隐藏
*
* @param x
* @param y
*/
@Override
public void scrollTo(int x, int y) {
scrollBy(offsetX - x, y);
}
public int getOffsetX() {
return offsetX;
}
@Override
public void setAdapter(Adapter adapter) {
setLayoutManager(new LinearLayoutManager(getContext(), LinearLayoutManager.HORIZONTAL, false));
super.setAdapter(adapter);
}
}
手指滑动ViewPager，保证选中的TabLayout的item在正中间
手指滑动ViewPager,TabLayout跟着滑动
手指点击TabLayout,ViewPager跟着滑动
手指滑动TabLayout,再点击TabLayout
手指滑动TabLayout,再触摸ViewPager
手指滑动TabLayout,再滑动ViewPager
今日头条存在一个体验不好的场景：快速滑动TabLayout,ViewPager在TabLayout停止滑动之前就停止了滑动，这时，将看不到indicator，然而小编的TabLayoutNiubility解决了这个问题
源码如下
package com.cy.tablayoutniubility;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import androidx.viewpager2.widget.ViewPager2;
import static androidx.viewpager2.widget.ViewPager2.SCROLL_STATE_IDLE;
/**
* @Description:
* @Author: cy
* @CreateDate: 2020/7/29 18:42
* @UpdateUser:
* @UpdateDate: 2020/7/29 18:42
* @UpdateRemark:
* @Version:
*/
public class TabLayoutMediatorVp2
{
private
TabLayoutNiubility tabLayout;
private
ViewPager2 viewPager2;
private
TabAdapter<T> tabAdapter;
private
int position_scroll_last
=
0;
private
int diff
=
0;
private
int diff_click
=
0;
private
int toScroll
=
0;
private
int offsetX_last
=
0;
private
int offsetX_last_click
=
0;
private
int offsetX_touch
=
0;
private
boolean rvScrolledByVp
=
false;
private
boolean rvScrolledByTouch
=
false;
private
boolean scrolledByClick
=
false;
private
int position_selected_last
=
0;
private
boolean op_click_last
=
false;
private
int click_position_last
=
-
1;
public
TabLayoutMediatorVp2(
TabLayoutNiubility
tabLayout,
final
ViewPager2
viewPager2) {
this
.tabLayout
= tabLayout;
this
.viewPager2
= viewPager2;
}
public
TabAdapter<T>
setAdapter(
final
FragmentPageAdapterVp2<T>
fragmentPageAdapter) {
tabAdapter
=
new
TabAdapter<T>() {
@Override
public
void
bindDataToView(
TabViewHolder
holder,
int
position,
T
bean,
boolean
isSelected) {
fragmentPageAdapter
.bindDataToTab( holder, position, bean, isSelected);
}
@Override
public
int
getItemLayoutID(
int
position,
T
bean) {
return fragmentPageAdapter
.getTabLayoutID(position, bean);
}
@Override
public
void
onItemClick(
TabViewHolder
holder,
int
position,
T
bean) {
//点击tabLayout的item,会先回调onPageSelected,然后回调onPageScrolled
//标志复位
rvScrolledByTouch
=
false;
offsetX_touch
=
0;
//标志：tablayout的滑动是由点击item触发的
scrolledByClick
=
true;
position_selected_last
= viewPager2
.getCurrentItem();
viewPager2
.setCurrentItem(position);
//让indicator立马指向currentItem
RecyclerView
.
ViewHolder viewHolder
= tabLayout
.getHorizontalRecyclerView()
.findViewHolderForAdapterPosition(viewPager2
.getCurrentItem());
if (viewHolder
!=
null) {
tabLayout
.getIndicatorView()
.getIndicator()
.setWidth_indicator(tabLayout
.getIndicatorView()
.getIndicator()
.getWidth_indicator_selected())
.setProgress((
int) (viewHolder
.itemView
.getLeft()
+ viewHolder
.itemView
.getWidth()
*
1f
/
2
- tabLayout
.getIndicatorView()
.getIndicator()
.getWidth_indicator()
/
2));
}
else {
//不可见，width_indicator为0
tabLayout
.getIndicatorView()
.getIndicator()
.setWidth_indicator(
0)
.invalidate();
}
fragmentPageAdapter
.onTabClick( holder, position, bean);
}
};
tabLayout
.getHorizontalRecyclerView()
.addOnScrollListener(
new
RecyclerView.
OnScrollListener() {
@Override
public
void
onScrolled(
@NonNull
RecyclerView
recyclerView,
int
dx,
int
dy) {
super
.onScrolled(recyclerView, dx, dy);
//如果是手指滑动tabLayout，需要记录滑动的距离
if (
!rvScrolledByVp) {
rvScrolledByTouch
=
true;
offsetX_touch
-= dx;
}
//indicator需要跟着滑动
RecyclerView
.
ViewHolder viewHolder
= tabLayout
.getHorizontalRecyclerView()
.findViewHolderForAdapterPosition(viewPager2
.getCurrentItem());
if (viewHolder
!=
null) {
tabLayout
.getIndicatorView()
.getIndicator()
.setWidth_indicator(tabLayout
.getIndicatorView()
.getIndicator()
.getWidth_indicator_selected())
.setProgress((
int) (viewHolder
.itemView
.getLeft()
+ viewHolder
.itemView
.getWidth()
*
1f
/
2
- tabLayout
.getIndicatorView()
.getIndicator()
.getWidth_indicator()
/
2));
}
else {
//不可见，width_indicator为0
tabLayout
.getIndicatorView()
.getIndicator()
.setWidth_indicator(
0)
.invalidate();
}
}
});
viewPager2
.registerOnPageChangeCallback(
new
ViewPager2.
OnPageChangeCallback() {
@Override
public
void
onPageSelected(
int
position) {
super
.onPageSelected(position);
//通知tabAdapter更新选中项
tabAdapter
.setPositionSelected(viewPager2
.getCurrentItem());
}
/**注意：滑动很快的时候，即使到了另外的page,positionOffsetPixels不一定会出现0
* @param position
* @param positionOffset
* @param positionOffsetPixels
*/
@Override
public
void
onPageScrolled(
int
position,
float
positionOffset,
int
positionOffsetPixels) {
super
.onPageScrolled(position,positionOffset,positionOffsetPixels);
int centerX
= (
int) (tabLayout
.getWidth()
*
1f
/
2);
//说明上次手指滑动了tabLayout，现在手指滑动viewpager,需要将tablayout复位
if (rvScrolledByTouch
&& offsetX_touch
!=
0) {
tabLayout
.getHorizontalRecyclerView()
.stopScroll();
//标志不是由手指滑动tablayout
rvScrolledByVp
=
true;
tabLayout
.getHorizontalRecyclerView()
.scrollBy(offsetX_touch,
0);
rvScrolledByVp
=
false;
//立刻复位
rvScrolledByTouch
=
false;
offsetX_touch
=
0;
//这里不能修改position_scroll_last，因为只要上次手指滑动了tablayout,然后手指滑动viewapger，onPageScrolled会被回调多次
//在后面去修改position_scroll_last即可
// position_scroll_last = position;
return;
}
//点击item后，onPageSelected先回调，然后还会继续回调onPageScrolled，直到onPageScrolled=position_selected，从page index 滑动到 page index+1，
//position == viewPager2.getCurrentItem() - 1说明点击的item在当前position之后
//position == viewPager2.getCurrentItem()说明点击的item在当前position之前
//viewpager滑动中，才处理，
if (scrolledByClick) {
if ((position
== viewPager2
.getCurrentItem()
-
1
|| position
== viewPager2
.getCurrentItem())) {
RecyclerView
.
ViewHolder viewHolder
= tabLayout
.getHorizontalRecyclerView()
.findViewHolderForAdapterPosition(viewPager2
.getCurrentItem());
if (viewHolder
!=
null) {
//indicator想要指向正中间，计算TabLayout需要滑动的距离
if (diff_click
==
0)
diff_click
= (
int) (viewHolder
.itemView
.getLeft()
+ viewHolder
.itemView
.getWidth()
*
1f
/
2
- centerX);
//获取tablayout的偏移量，永远<=0
if (offsetX_last_click
==
0)
offsetX_last_click
= tabLayout
.getHorizontalRecyclerView()
.getOffsetX();
if (positionOffset
!=
0) {
//scrollBy调用一次，onScrolled回调一次
//标志不是由手指滑动tablayout
rvScrolledByVp
=
true;
//往右滑
if (position_selected_last
< viewPager2
.getCurrentItem()) {
tabLayout
.getHorizontalRecyclerView()
.scrollTo((
int) (offsetX_last_click
- (diff_click
* positionOffset)),
0);
}
else {
//往左滑
tabLayout
.getHorizontalRecyclerView()
.scrollTo((
int) (offsetX_last_click
- (diff_click
* (
1
- positionOffset))),
0);
}
rvScrolledByVp
=
false;
}
}
else {
//不可见，width_indicator为0
tabLayout
.getIndicatorView()
.getIndicator()
.setWidth_indicator(
0)
.invalidate();
}
}
position_scroll_last
= position;
return;
}
/**
* 手指左右滑动Viewpager，触发下面所有代码
*/
TabViewHolder viewHolder
= (
TabViewHolder) tabLayout
.getHorizontalRecyclerView()
.findViewHolderForAdapterPosition(position);
if (viewHolder
!=
null) {
int width_half
= (
int) (viewHolder
.itemView
.getWidth()
*
1f
/
2);
int left
= viewHolder
.itemView
.getLeft();
int space
= tabLayout
.getHorizontalRecyclerView()
.getItemDecoration()
.getSpace_horizontal();
TabViewHolder viewHolder_behind
= (
TabViewHolder) tabLayout
.getHorizontalRecyclerView()
.findViewHolderForAdapterPosition(position
+
1);
if (position
==
0) {
//TabLayout刚显示，indicator会指向第0个item
diff
=
0;
offsetX_last
=
0;
if (viewHolder_behind
!=
null)
//计算indicator指向下一个item需要滑动的距离
toScroll
= (
int) (width_half
+ tabLayout
.getHorizontalRecyclerView()
.getItemDecoration()
.getSpace_horizontal()
+ viewHolder_behind
.itemView
.getWidth()
*
1f
/
2);
}
else
if (position_scroll_last
< position) {
//说明从page index 滑动到了page index+1,
if (viewHolder_behind
!=
null) {
//indicator想要指向正中间，计算TabLayout需要滑动的距离
diff
= (
int) (viewHolder_behind
.itemView
.getLeft()
+ viewHolder_behind
.itemView
.getWidth()
*
1f
/
2
- centerX);
//下一个item都在正中间的前面，无需滑动，而且可以避免出现负数导致recyclerView抖动
if (diff
<
0) diff
=
0;
//获取上次tablayout的偏移量，永远<=0
offsetX_last
= tabLayout
.getHorizontalRecyclerView()
.getOffsetX();
//计算indicator指向下一个item需要滑动的距离
toScroll
= (
int) (width_half
+ tabLayout
.getHorizontalRecyclerView()
.getItemDecoration()
.getSpace_horizontal()
+ viewHolder_behind
.itemView
.getWidth()
*
1f
/
2);
}
}
else
if (position_scroll_last
> position) {
//说明从page index 滑动到了page index-1
//indicator想要指向正中间，计算TabLayout需要滑动的距离
diff
= (
int) (left
+ width_half
- centerX);
//position的item在正中间的后面，无需滑动，而且可以避免出现正数导致recyclerView抖动
if (diff
>
0) diff
=
0;
//获取上次tablayout的偏移量，永远<=0
offsetX_last
= tabLayout
.getHorizontalRecyclerView()
.getOffsetX();
if (viewHolder_behind
!=
null)
//计算indicator指向position的item需要滑动的距离
toScroll
= (
int) (width_half
+ tabLayout
.getHorizontalRecyclerView()
.getItemDecoration()
.getSpace_horizontal()
+ viewHolder_behind
.itemView
.getWidth()
*
1f
/
2);
}
else
if (op_click_last) {
//如果position_scroll_last==position,并且上次操作是点击item,
if (position
== click_position_last) {
//说明现在是正要从page index 滑动到page index+1
if (viewHolder_behind
!=
null) {
//indicator想要指向正中间，计算TabLayout需要滑动的距离
diff
= (
int) (viewHolder_behind
.itemView
.getLeft()
+ viewHolder_behind
.itemView
.getWidth()
*
1f
/
2
- centerX);
//获取上次tablayout的偏移量，永远<=0
offsetX_last
= tabLayout
.getHorizontalRecyclerView()
.getOffsetX();
//计算indicator指向position的item需要滑动的距离
toScroll
= (
int) (width_half
+ tabLayout
.getHorizontalRecyclerView()
.getItemDecoration()
.getSpace_horizontal()
+ viewHolder_behind
.itemView
.getWidth()
*
1f
/
2);
}
}
op_click_last
=
false;
}
//diff==0,无需滑动，positionOffset==0,无需滑动，当前position和上次滑动的position相等，才执行滑动操作
if (diff
!=
0
&& positionOffset
!=
0
&& position_scroll_last
== position) {
//标志，tabLayout滑动，不是因为手指滑动tablayout导致的
rvScrolledByVp
=
true;
if (diff
>
0) {
//scrollBy调用一次，onScrolled回调一次
//手指往左滑动，positionOffset由小变大
tabLayout
.getHorizontalRecyclerView()
.scrollTo((
int) (offsetX_last
- (diff
* positionOffset)),
0);
}
else {
//手指往右滑动，positionOffset由大变小
tabLayout
.getHorizontalRecyclerView()
.scrollTo((
int) (offsetX_last
- (diff
* (
1
- positionOffset))),
0);
}
//标志复位
rvScrolledByVp
=
false;
}
//计算Width_indicator,Width_indicator由小变大再变小，2个item中间时最大
tabLayout
.getIndicatorView()
.getIndicator()
.setWidth_indicator(
Math
.max(tabLayout
.getIndicatorView()
.getIndicator()
.getWidth_indicator_selected(),
(
int) (tabLayout
.getIndicatorView()
.getIndicator()
.getWidth_indicator_selected()
+
(positionOffset
==
0
?
0
: tabLayout
.getIndicatorView()
.getIndicator()
.getWidth_indicator_max()
* (
0.5
-
Math
.abs(
0.5
- positionOffset))))))
.setProgress((
int) (left
+ width_half
- tabLayout
.getIndicatorView()
.getIndicator()
.getWidth_indicator()
/
2
+ (toScroll
* positionOffset)));
if (toScroll
!=
0)
//手指往左滑动，positionOffset由小变大
//手指往右滑动，positionOffset由大变小
if (viewHolder_behind
!=
null)
fragmentPageAdapter
.onTabScrolled(viewHolder, position,
false,
1
- positionOffset,
viewHolder_behind, position
+
1,
true, positionOffset);
}
else {
//viewpager嵌套viewpager的时候，内层viewpager向右滑动了以后又向左滑动，会导致tablayout
//position对应的item不可见，所以要滑动到对应的position
tabLayout
.getHorizontalRecyclerView()
.scrollToPosition(position);
viewHolder
= (
TabViewHolder) tabLayout
.getHorizontalRecyclerView()
.findViewHolderForAdapterPosition(position);
//scrollToPosition一调用，不会立马滑动完毕，所以还会有存在null的时候，
if(viewHolder
!=
null){
int width_half
= (
int) (viewHolder
.itemView
.getWidth()
*
1f
/
2);
int left
= viewHolder
.itemView
.getLeft();
tabLayout
.getIndicatorView()
.getIndicator()
.setWidth_indicator(tabLayout
.getIndicatorView()
.getIndicator()
.getWidth_indicator_selected())
.setProgress((
int) (left
+ width_half
- tabLayout
.getIndicatorView()
.getIndicator()
.getWidth_indicator()
/
2));
}
else {
tabLayout
.getIndicatorView()
.getIndicator()
.setWidth_indicator(
0)
.invalidate();
}
}
position_scroll_last
= position;
}
@Override
public
void
onPageScrollStateChanged(
int
state) {
switch (state) {
case
SCROLL_STATE_IDLE
:
//记录上次操作的是点击item
if (scrolledByClick) {
click_position_last
= viewPager2
.getCurrentItem();
op_click_last
=
true;
}
//标志复位
scrolledByClick
=
false;
diff_click
=
0;
offsetX_last_click
=
0;
break;
}
}
});
tabLayout
.setAdapter(tabAdapter);
viewPager2
.setAdapter(fragmentPageAdapter);
return tabAdapter;
}
}
处理过程超鸡儿复杂，千万别想着能看懂，要是能看懂，只能说明你是万中无一的绝世高手，能知道大概干了些什么就可以了。
TabLayout的item宽度均分
用LinearLayout做tablayout，每个item的weight设置为1
removeAllViews();
for (int i = 0; i < tabNoScrollAdapter.getItemCount(); i++) {
TabNoScrollViewHolder tabNoScrollViewHolder = tabNoScrollAdapter.onCreateViewHolder(i, tabNoScrollAdapter.getList_bean().get(i), this);
tabNoScrollViewHolder.setPositionAdapter(i);
sparseArrayViewHolder.put(i, tabNoScrollViewHolder);
addView(tabNoScrollViewHolder.itemView, new LinearLayout.LayoutParams(0, ViewGroup.LayoutParams.MATCH_PARENT, 1));
ItemChanged(i);
}
RecyclerView的item刷新如何做到不闪烁
禁用默认的刷新动画
SimpleItemAnimator simpleItemAnimator = (SimpleItemAnimator) getItemAnimator();
if (simpleItemAnimator != null) simpleItemAnimator.setSupportsChangeAnimations(false);
UML类图如下
面向接口编程（面向多态编程）的思想
小编特别喜欢JAVA这门语言，小编个人认为JAVA将面向对象编程的思想展现的淋漓尽致。
整个轮子用得最多的编程思想就是多态，多态是设计模式和框架的基础。
接口和泛型是实现多态的2把利器。
编程思想暂且稍微透露，后面小编会专门出一个SDK开发入门教程，详细讲述设计模式和多态，敬请关注。
欢迎联系、指正、批评
Github:https://github.com/AnJiaoDe
CSDN：https://blog.csdn.net/confusing_awakening
ffmpeg入门教程:https://blog.csdn.net/confusing_awakening/article/details/102007792
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