始終調用MotionEvent.Action_UP

Question

這是我的onTouchEvent（MotionEvent event）的代碼：

@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;
}

這里的問題是，無論我實際上是否將手指從屏幕上移開，總是會調用ACTION_UP。 我在調試模式下運行它，同時在案例MotionEvent.ACTION_UP上放置了一個斷點，當我按下（但未釋放）時，它被調用了。 有人可以解釋為什么會這樣嗎？

Answer 1

我分析了您的代碼，我認為這僅僅是因為您沒有在Action_Down和Action_Up案例之間插入中斷。

試試下面的代碼.....

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;

希望對您有幫助...