iOS  Programming  UIGestureRecognizer and UIMenuControllerA UIGestureRecognizer intercepts touches that are on their way to being ...
iOS Programming UIGestureRecognizer and UIMenuController
A UIGestureRecognizer intercepts touches that are on their way to being handled by a view.
一个UIGestureRecognizer拦截touches 在他们被一个view处理的路上。
When it recognizes a particular gesture, it sends a message to the object of your choice.
当它检测到一个特殊的手势时,它就会发送一个消息给你选中的特殊的对象。
There are several types of gesture recognizers built into the SDK.
在内部的SDK中,有一些特殊的手势类型。
1 UIGestureRecognizer Subclasses
You do not instantiate UIGestureRecognizer itself. Instead, there are a number of subclasses of UIGestureRecognizer, and each one is responsible for recognizing a particular gesture.
你并不会实例化UIGestureRecognizer自身,而是有一些UIGestureRecognizer的子类,这些子类负责鉴别一个特殊的手势。
To use an instance of a UIGestureRecognizer subclass, you give it a target-action pair and attach it to a view.
为了实例化UIGestureRecognizer子类,你给了它一个target-action pair 并把它与一个view 联系在一起。
Whenever the gesture recognizer recognizes its gesture on the view, it will send the action message to its target.
当一个gesture recognizer 识别出了在view 上的手势,它将会发送动作信息给它的target。
- (void)action:(UIGestureRecognizer *)gestureRecognizer;
When recognizing a gesture, the gesture recognizer intercepts the touches destined for the view
当鉴别出一个手势后,它的gesture recognizer 为指定的view解析这个touches。
Thus, a view with gesture recognizers may not receive the typical UIResponder messages like touchesBegian:withEvent:.
因此一个有gesture recognizers的view 可能不接受典型的UIResponder 消息,比如touchesBegian:withEvent
2 Detecting Taps with UITapGestureRecognizer
The first UIGestureRecognizer subclass you will use is UITapGestureRecognizer.
第一个你将会使用的UIGestureRecognizer子类是UITapGestureRecognizer。
When the user taps the screen twice, all of the lines on the screen will be cleared.
当用户点击屏幕两次的时候,所有的线就会被清除掉。
In BNRDrawView.m, instantiate a UITapGestureRecognizer that requires two taps to fire in initWithFrame:.
UITapGestureRecognizer *doubleTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self
action:@selector(doubleTap:)]; doubleTapRecognizer.numberOfTapsRequired = 2;
[self addGestureRecognizer:doubleTapRecognizer];
- (void)doubleTap:(UIGestureRecognizer *)gr
{
原标题:iOS Programming UIGestureRecognizer and UIMenuController
关键词:IOS
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