android - MotionEvent.Action_UP 总是被调用

Question

这是我的 onTouchEvent(MotionEvent 事件)的代码:

@Override
public boolean onTouchEvent(MotionEvent event){
    int action = event.getAction();
    int x = Math.round(event.getX());
    int y = Math.round(event.getY());
    //play is an imageView
    int viewLeft = play.getLeft();
    int viewRight = play.getRight();
    int viewTop = play.getTop();
    int viewBottom = play.getBottom();
    boolean onPoint = false;

    switch (action) {
        case MotionEvent.ACTION_DOWN:
            //Checks if the touched area falls within the imageView play
            if ((x >= viewLeft && x <= viewRight) && (y >= viewTop && y <= viewBottom)) {
                onPoint = true;
                play.setImageResource(R.drawable.playyellow);
            }
        case MotionEvent.ACTION_UP:
            //if the finger is lifed on the imageView, the intent is called
            play.setImageResource(R.drawable.play1);
            if (onPoint) {
                if ((x >= viewLeft && x <= viewRight) && (y >= viewTop && y <= viewBottom)) {
                    Intent i = new Intent(this, InGame.class);
                    startActivity(i);
                }
            }

    }
    return true;
}

这里的问题是 ACTION_UP 总是被调用，无论我是否真的将手指从屏幕上移开。我在 Debug模式下运行它，同时在案例 MotionEvent.ACTION_UP 上放置一个断点，当我按下(但没有释放)时，它被调用了。有人可以解释为什么会这样吗？

Answer 1

我分析了您的代码，我认为这只是因为您没有在 Action_Down 和 Action_Up 情况之间插入中断。

试试下面的代码......

switch (action) {
    case MotionEvent.ACTION_DOWN:
        //Checks if the touched area falls within the imageView play
        if ((x >= viewLeft && x <= viewRight) && (y >= viewTop && y <= viewBottom)) {
            onPoint = true;
            play.setImageResource(R.drawable.playyellow);
        }
         break;
    case MotionEvent.ACTION_UP:
        //if the finger is lifed on the imageView, the intent is called
        play.setImageResource(R.drawable.play1);
        if (onPoint) {
            if ((x >= viewLeft && x <= viewRight) && (y >= viewTop && y <= viewBottom)) {
                Intent i = new Intent(this, InGame.class);
                startActivity(i);
            }
        }

}
return true;

希望对你有帮助...