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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