添加新视图时，android scrollview滚动到顶部方向

Question

In scrollview, if I add any view in middle, normally all the views below the added view scrolls downside. But I want to scroll the top views of added view to upside without disturbing the bottom views. Is it possible in scrollview , please help me ?

In the figure , If view 4 was added , then view 1 has to be scrolled upwards , without changing the positions of view 2 and view 3.

Answer 1

您可以获取要添加的视图的高度，然后手动滚动滚动视图，即多个像素

scrollView.scrollBy(0, viewAdded.getHeight())

Answer 2

I've been wanting to try this question for quite some time, I finally got the chance today. The method is pretty simple (in fact, @dweebo already mentioned it earlier) - we move the ScrollView up as we add the view. For getting precise (and valid) dimensions when adding, we use a ViewTreeObserver . Here's the code you can get hints from:

    // Getting reference to ScrollView
    final ScrollView scrollView = (ScrollView) findViewById(R.id.scrollView);
    // Assuming a LinearLayout container within ScrollView
    final LinearLayout parent = (LinearLayout) findViewById(R.id.parent);

    // The child we are adding
    final View view = new View(ScaleActivity.this);
    LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 100);
    view.setLayoutParams(params);

    // Finally, adding the child
    parent.addView(view, 2); // at index 2

    // This is what we need for the dimensions when adding
    ViewTreeObserver viewTreeObserver = parent.getViewTreeObserver();
    viewTreeObserver.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
        @Override
        public boolean onPreDraw() {
            parent.getViewTreeObserver().removeOnPreDrawListener(this);

            scrollView.scrollBy(0, view.getHeight());
            // For smooth scrolling, run below line instead
            // scrollView.smoothScrollBy(0, view.getHeight())

            return false;
        }
    });