将UITouch位置与UIImageView矩形进行比较 [英] Comparing a UITouch location to UIImageView rectangle

问题描述

我有以下代码来确定触摸是否在我的表单元格中的图像视图内。但是，它不工作。我比较两个与CGRectContainsPoint然而，它不工作。下面是代码：

I have the following code to determine if a touch is within an image view in my table cell. However, it doesn't work. I compared the two with CGRectContainsPoint however, it doesn't work. Here is the code:

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event    
{
     // Declare the touch and get it's location

     UITouch *touch = [touches anyObject];

     CGPoint touchLocation = [touch locationInView:self];

     if (CGRectContainsPoint(myImageView.frame, touchLocation))
     {
        NSLog(@"Tapped image view");
     }    
}

感谢您的帮助！

推荐答案

但它不起作用。

However, it doesn't work.

请更具体。

 UITouch *touch = [touches anyObject];

为什么不检查<而不是简单的随机*选择他们？

Why not examine every touch, and not simply a random* pick of them?

* anyObject 说，你不能保证它会给你一个。你甚至不能保证它是随机的;它可以是每次相同的对象。墨菲定律说，无论是否是随机的，都是错误的。

*The documentation for anyObject says that you are not guaranteed which one it will give you. You are not even guaranteed that it will be random; it could be the same object every time. Murphy's Law says that, whether it is random or not, it will be the wrong one.

 CGPoint touchLocation = [touch locationInView:self];
 if (CGRectContainsPoint(myImageView.frame, touchLocation))

您的框架是在您的superview的坐标系统; [touch locationInView：self] 返回您的坐标系统中的接触点。你想在 bounds 中测试，这是在你的坐标系统中。 本文档介绍了区别。

Your frame is in your superview's co-ordinate system; [touch locationInView:self] returns the touch point in your co-ordinate system. You want to test within bounds, which is in your co-ordinate system. The documentation explains the difference.

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