beginDelayedTransition用法

要改变某个控件的位置，可以用修改布局参数后setLayoutParams，如果想给这个过程加上动画效果，则可以在父节点上调用TransitionManager.beginDelayedTransition

private void changePosition() {
    TransitionManager.beginDelayedTransition(viewRoot);

    LinearLayout.LayoutParams lp = (LinearLayout.LayoutParams) square.getLayoutParams();
    if (positionChanged) {
        lp.gravity = Gravity.CENTER;
    } else {
        lp.gravity = Gravity.LEFT;
    }
    positionChanged = !positionChanged;
    square.setLayoutParams(lp);
}