Android如何以编程方式将ScrollView子级移到顶部

Question

I have a ScrollView which contains numerous views on LinearLayout .I have implemented expand and collapse layouts. OnClick of view,it either expand or collapse.So when a view expands,I want to programmatically move ScrollView such that the view comes on top of the screen.See image below

I want to move the ScrollView to the length shown on red line. The child of ScrollView contains a TextView (4:Status bar notification) and an ImageView .Further ScrollView may or maynot contains views above or below the TextView ImageView combination. I have used a CustomScrollView where I findout scroll Y by

public int newY=0;
@Override
protected void onScrollChanged(int X, int Y, int oldX, int oldY) {
    super.onScrollChanged(X, Y, oldX, oldY);
    this.newY=Y;
}

For that I have used following logic

 public void translateView(View view){
    int[] xy =new int[2];
   //view = ImageView
    view.getLocationOnScreen(xy);
    int scrollY = xy[1]+view.getBottom();
    //screenHeight =ScreenHeight of the phone
    if(scrollY>screenHeight){
      //heading textView
        textView.getLocationOnScreen(xy);
        int diff = screenHeight-xy[1];
        diff =Math.abs(diff);
        int moveHeight = (int) (scrollView.newY+diff);
        scrollView.smoothScrollTo(0, moveHeight);

    }
}

So basically what I am trying to do is finding the difference between y position of TextView and subtracting it with screen height and scrolling the ScrollView to those difference,so that the view is shown on top.But it is not working.Any Idea on how to achieve this.

Answer 1

I just found what I was doing wrong. Each screen comprises of StatusBar and in my case ActionBar .So when I was calculating the View Y position,I was calculating from top of the screen and whenever I use the increment value for ScrollView Scroll ,I was moving my view to top of the screen.So the actual solution would be

public void translateView(final View view){
    int[] xy =new int[2];
    view.getLocationOnScreen(xy);
    int scrollY = xy[1]+view.getBottom();


    if(scrollY>DataHolder.screenHeight){
        handle.getLocationOnScreen(xy);
        int actualY=xy[1]-DataHolder.actionbarHeight-DataHolder.statusBarHeight;
        int moveHeight = (int) (scrollView.newY+actualY);
        scrollView.smoothScrollTo(0, moveHeight);   
    }
}

So by doing this my view automatically reaches the top of the screen