listView实现阻尼效果

自定义类继承ListView
public class BounceListView extends ListView{
    private static final int MAX_Y_OVERSCROLL_DISTANCE = 200;
    
    private Context mContext;
private int mMaxYOverscrollDistance;

public BounceListView(Context context){
super(context);
mContext = context;
initBounceListView();
}

public BounceListView(Context context, AttributeSet attrs){
super(context, attrs);
mContext = context;
initBounceListView();
}

public BounceListView(Context context, AttributeSet attrs, int defStyle){
super(context, attrs, defStyle);
mContext = context;
initBounceListView();
}

private void initBounceListView(){
//get the density of the screen and do some maths with it on the max overscroll distance
//variable so that you get similar behaviors no matter what the screen size

final DisplayMetrics metrics = mContext.getResources().getDisplayMetrics();
        final float density = metrics.density;
        
mMaxYOverscrollDistance = (int) (density * MAX_Y_OVERSCROLL_DISTANCE);
}

@Override
protected boolean overScrollBy(int deltaX, int deltaY, int scrollX, int scrollY, int scrollRangeX, int scrollRangeY, int maxOverScrollX, int maxOverScrollY, boolean isTouchEvent){ 
//This is where the magic happens, we have replaced the incoming maxOverScrollY with our own custom variable mMaxYOverscrollDistance; 
return super.overScrollBy(deltaX, deltaY, scrollX, scrollY, scrollRangeX, scrollRangeY, maxOverScrollX, mMaxYOverscrollDistance, isTouchEvent);  
}

}
布局
 <com.example.li.BounceListView
        android:id="@+id/listView"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:scrollbars="none"
/>