android - 屏幕滚动后执行操作

Question

我试图在水平滚动屏幕后显示 toast 。滚动可以发生在屏幕上的任何位置，但我希望只有当屏幕从右向左滚动时才会出现 toast。我试过这个:

HorizontalScrollView headerScrollView = new HorizontalScrollView(this);

       headerScrollView.setOnTouchListener(new View.OnTouchListener() {

           @Override
           public boolean onTouch(View v, MotionEvent event) {
               Toast.makeText(Verbs.this, "The screen has been scrolled", Toast.LENGTH_LONG).show();
               return true;
           }
       });

Answer 1

您必须覆盖 setOnScrollChangeListener 方法来检测从右向左滚动。

HorizontalScrollView headerScrollView = new HorizontalScrollView(this);
    headerScrollView.setOnScrollChangeListener(new View.OnScrollChangeListener() {
        @Override
        public void onScrollChange(View v, int scrollX, int scrollY, int oldScrollX, int oldScrollY) {
            if (scrollX > oldScrollX) {
                Toast.makeText(Verbs.this, "moved right to left", Toast.LENGTH_LONG).show();
            }
        }
    });