UIScrollView的touchesShouldBegin: NSSet只是一个NSString
我有一个 UIScrollView 的子类，它也是委托。
当我调用下一个协议函数时：
- (BOOL)touchesShouldBegin:(NSSet *)touches withEvent:(UIEvent *)event inContentView:(UIView *)view
{
id element;
NSEnumerator *setEnum = [touches objectEnumerator];
while ((element = [setEnum nextObject]) != nil)
{
NSLog(@"element:%@", element);
}
return [super touchesShouldBegin:touches withEvent:event inContentView:view];
}
NSLog 显示的唯一内容是：
element:<UITouch: 0x15a9a0> phase: Ended tap count: 3 window: <UIWindow: 0x392390; frame = (0 0; 320 480); layer = <UIWindowLayer: 0x382cd0>> view: <UIButton: 0x3a5e90; frame = (0 0; 106 138); opaque = NO; layer = <CALayer: 0x3a3e90>> location in window: {228, 126} previous location in window: {227, 126} location in view: {89.6667, 77} previous location in view: {88.3333, 77}
问题是，它将 NSSet 的内容显示为一个大 NSString。如果我从 objectEnumerator 询问 allObjects，我只会得到 NSArray 中的一个对象。与 NSLog 显示的对象（NSString）完全相同。
有人可以告诉我我是否做错了什么，或者 NSSet 只给出一个 NSString 是否不正常。
谢谢你！
I have a subclass of UIScrollView, it is also the delegate.
When I have the next protocol function called:
- (BOOL)touchesShouldBegin:(NSSet *)touches withEvent:(UIEvent *)event inContentView:(UIView *)view
{
id element;
NSEnumerator *setEnum = [touches objectEnumerator];
while ((element = [setEnum nextObject]) != nil)
{
NSLog(@"element:%@", element);
}
return [super touchesShouldBegin:touches withEvent:event inContentView:view];
}
The only thing that NSLog is showing is:
element:<UITouch: 0x15a9a0> phase: Ended tap count: 3 window: <UIWindow: 0x392390; frame = (0 0; 320 480); layer = <UIWindowLayer: 0x382cd0>> view: <UIButton: 0x3a5e90; frame = (0 0; 106 138); opaque = NO; layer = <CALayer: 0x3a3e90>> location in window: {228, 126} previous location in window: {227, 126} location in view: {89.6667, 77} previous location in view: {88.3333, 77}
The problem is, it shows the content of the NSSet as one big NSString. If I ask allObjects from the objectEnumerator, I just get one object in an NSArray. Exactly the same object (the NSString) as NSLog is showing.
Could someone please tell me if I am doing something wrong, or if it is not normal that the NSSet is just giving one NSString.
Thank you!
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NSLog()输出是在对象上调用description方法的结果。NSLog()输出被设计为人类可读，仅用于调试。UITouch。描述的其余部分仅显示UITouch的一些有趣的值。尝试：
等等，你会发现它不仅仅是一个字符串。
另外，不需要显式的
NSEnumerator，可以使用快速枚举：您可以将代码简化为：The
NSLog()output is the result of thedescriptionmethod called on the object.NSLog()output is designed to be human readable for debugging only.<UITouch: 0x15a9a0>indicates the the object is aUITouchat address 0x15a9a0. The rest of the description just displays some interesting values of theUITouch.Try:
etc. and you will se that it is not just a string.
As an aside there is no need for an explicit
NSEnumerator, fast enumeration ca be used: you can simplify the code to:NSSet Touchs 是一组 UITouch 实例，而不是 NSString。当您将其发送到 NSLog 时，它会调用 UITouch 实例的“description”方法，该方法返回一个 NSString。
The NSSet touches is a set of UITouch instances, not NSStrings. When you send it to NSLog, it calls the "description" method of the UITouch instance which does return an NSString.