Android:检测用户是否触摸并拖出按钮区域？

Question

在Android中，我们如何检测用户是否触摸按钮并拖出该按钮的区域？

Answer 1

检查 MotionEvent.MOVE_OUTSIDE: 检查 MotionEvent.MOVE:

private Rect rect;    // Variable rect to hold the bounds of the view

public boolean onTouch(View v, MotionEvent event) {
    if(event.getAction() == MotionEvent.ACTION_DOWN){
        // Construct a rect of the view's bounds
        rect = new Rect(v.getLeft(), v.getTop(), v.getRight(), v.getBottom());

    }
    if(event.getAction() == MotionEvent.ACTION_MOVE){
        if(!rect.contains(v.getLeft() + (int) event.getX(), v.getTop() + (int) event.getY())){
            // User moved outside bounds
        }
    }
    return false;
}

注意:如果您想以 Android 4.0 为目标，则会打开一个充满新可能性的世界: http://developer.android.com/reference/android/view/MotionEvent.html#ACTION_HOVER_ENTER