当触发UIButton时,如何获得touchesBegan坐标？

Question

我有一个touchesBegan方法设置为在用户触摸屏幕时拾取坐标.它很有效,除非我触摸UIButton.如何使按钮触发touchesBegan方法呢？

Answer 1

将事件处理程序添加到按钮,如下所示,

[myButton addTarget:self action:@selector(dragBegan:withEvent:) forControlEvents: UIControlEventTouchDown];
[myButton addTarget:self action:@selector(dragMoving:withEvent:) forControlEvents: UIControlEventTouchDragInside];
[myButton addTarget:self action:@selector(dragEnded:withEvent:) forControlEvents: UIControlEventTouchUpInside | UIControlEventTouchUpOutside];

处理事件如下,您可以从事件ev获取触点,如下所示,

- (void)dragBegan:(UIControl *)c withEvent:ev {
    NSLog(@"dragBegan......");
    UITouch *touch = [[ev allTouches] anyObject];
    CGPoint touchPoint = [touch locationInView:self.view];
    NSLog(@"Touch x : %f y : %f", touchPoint.x, touchPoint.y);
}

- (void)dragMoving:(UIControl *)c withEvent:ev {
    NSLog(@"dragMoving......");
}

- (void)dragEnded:(UIControl *)c withEvent:ev {
    NSLog(@"dragEnded......");
}

这不是我自己的答案.我从http://sree.cc/iphone/handling-touche-events-for-uibuttons-in-iphone那里得到了这段代码并进行了一些小改动.