Activity中通过标签获取当前Fragment

Posted 2020-09-02 robert_hly

初始化完成之后才有数据，否则获取不到

　　String tag = "android:switcher:"+viewPager.getId()+":"+viewPager.getCurrentItem();

　　Fragment fg = getSupportFragmentManager().findFragmentByTag(tag);

　　if (fg == null) {
　　    return;
　　}

　　switch (viewPager.getCurrentItem()) {
   　　 case 0:
       　　       ((Fragment1)fg).updateUI();
       　　　　 break;
 　　   case 1:
        　　    ((Fragment2) fg).upDateUI();
    　　   break;
 　　   case 2:
     　　　　 ((Fragment3) fg).upDateUI();
     　　   break;

　　}

 

//ViewPage滑动变化监听

 viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
             //   doSomething
            }

            @Override
            public void onPageSelected(int position) {
                     switch (position){
                  　　  case 0:
              　　     //   doSomething
              　　          break;
          　　          case 1:
           　　            //   doSomething

            　　　　   break;
                　　    case 2:
                　　        //   doSomething
                   　　     break;
             　　   }
              }

            @Override
            public void onPageScrollStateChanged(int state) {
                //完全隐藏或显示时
                if (state == 0) {
                      //   doSomething
                }
             }
     });