Android listview在滾動時獲取大多數中心視圖位置

Question

我正在嘗試獲取大多數中心元素視圖位置的listview。

listview center view

public void getPos(final ListView listView) { 
     int firstPos = listView.getFirstVisiblePosition(); 
     int lastPos = listView.getLastVisiblePosition(); 
     int count = lastPos - firstPos; 
     int viewPosition = (count - ((int) count/2)); 
     //int viewPosition = (count - ((int) count/2)+1); 
} 

，並試圖與屏幕的X，Y

Display display = getWindowManager().getDefaultDisplay(); 
     final Point size = new Point(); 
     display.getSize(size); 
     float height = size.y; 
     float centerY=height/2; 

    listView.setOnScrollListener(new AbsListView.OnScrollListener() { 
     public void onScroll(final AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { 
      // TODO Auto-generated method stub 

     } 

     public void onScrollStateChanged(AbsListView view, int scrollState) { 
      //    Log.i("Yes1", "Here"); 
      if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_IDLE) { 
       if (scrollState == SCROLL_STATE_IDLE) { 
        final ListView listView = (ListView) view; 
        for (int i = 0; i < listView.getLastVisiblePosition(); i++) { 
         final View firstView = listView.getChildAt(i); 
         if (firstView != null) { 
          Log.i("Height", centerY + " | " + firstView.getY()); 
         } 
        } 
       } 
      } 
     } 
    }); 

我上面的方法試過，但同時向上和向下滾動沒有得到準確的結果。任何一個有解決方案如何在listview中獲得最中心的視圖位置？

Answer 1

試試這個：

   String[] values = new String[]{"Android List View", 
         "Adapter implementation", 
         "Simple List View In Android", 
         "Create List View Android", 
         "Android Example", 
         "List View Source Code", 
         "List View Array Adapter", 
         "Adapter implementation", 
         "Simple List View In Android", 
         "Create List View Android", 
         "Android Example", 
         "List View Source Code", 
         "List View Array Adapter", 
         "Adapter implementation", 
         "Simple List View In Android", 
         "Create List View Android", 
         "Android Example", 
         "List View Source Code", 
         "List View Array Adapter", 
         "Adapter implementation", 
         "Simple List View In Android", 
         "Create List View Android", 
         "Android Example", 
         "List View Source Code", 
         "List View Array Adapter", 
         "Adapter implementation", 
         "Simple List View In Android", 
         "Create List View Android", 
         "Android Example", 
         "List View Source Code", 
         "List View Array Adapter", 
         "Adapter implementation", 
         "Simple List View In Android", 
         "Create List View Android", 
         "Android Example", 
         "List View Source Code", 
         "List View Array Adapter", 
         "Adapter implementation", 
         "Simple List View In Android", 
         "Create List View Android", 
         "Android Example", 
         "List View Source Code", 
         "List View Array Adapter", 
         "Android Example List View" 
       }; 



       final ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, 
         R.layout.row_temp, R.id.label_tv, values); 
       final ListView listView = new ListView(this); 
       listView.setAdapter(adapter); 
       setContentView(listView); 

       listView.setOnScrollListener(new AbsListView.OnScrollListener() { 
        public void onScroll(final AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { 
         // TODO Auto-generated method stub 

        } 

        public void onScrollStateChanged(AbsListView view, int scrollState) { 
         if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_IDLE) { 
          for(int i=0;i<adapter.getCount();i++){ 
           if(listView.getChildAt(i) != null) { 
            TextView childView = (TextView) listView.getChildAt(i).findViewById(R.id.label_tv); 
            if (childView != null) { 
             childView.setBackgroundColor(Color.GREEN); 
            } 
           } 
          } 

          int centerItemPosition = ((listView.getLastVisiblePosition() - listView.getFirstVisiblePosition())/2); 
          TextView centerView =(TextView)listView.getChildAt(centerItemPosition).findViewById(R.id.label_tv); 
          centerView.setBackgroundColor(Color.RED); 
         } 
        } 
       }); 

row_temp的Xml

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:orientation="vertical" android:layout_width="match_parent" 
android:layout_height="match_parent"> 
<TextView 
    android:layout_width="match_parent" 
    android:id="@+id/label_tv" 
    android:textColor="@android:color/white" 
    android:text="skdjfksdf" 
    android:gravity="center" 
    android:padding="50dp" 
    android:background="@color/colorPrimaryDark" 
    android:layout_height="wrap_content" /> 

</LinearLayout> 

Output