當UIButton被觸發時，你如何獲得touchesBegan座標？

Question

我有一個touchesBegan方法設置爲在用戶觸摸屏幕時拾取座標。除了當我觸及一個UIButton時，它的效果很好。我怎樣才能讓按鈕觸發touchesBegan方法呢？

Answer 1

事件處理程序添加到按鈕，類似於以下，

[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]; 

處理事件，如下，您可以從事件EV如下，獲得觸摸點

- (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......"); 
} 

這不是我自己的答案。我從http://sree.cc/iphone/handling-touche-events-for-uibuttons-in-iphone得到了這段代碼，並做了一些小改動。

Answer 2

嘗試覆蓋UIButton類和touchesBegan方法調用[super touchesBegan ..]。