//

 //  TouchView.h

 //  LessonUIControlAndSubClass

 #import <UIKit/UIKit.h>

 @class TouchView;

 //1.制定协议，协议名字格式：类名+Delegate

 @protocol TouchViewDelegate <NSObject>

 @optional

 - (void)touchBegan:(TouchView *)touchView;

 - (void)touchMoved:(TouchView *)touchView;

 - (void)touchEnded:(TouchView *)touchView;

 - (void)touchCancelled:(TouchView *)touchView;

 @end

 @interface TouchView : UIView

 //2.写属性，属性名delegate，类型是id,并且要遵守协议<类名Delegate>

 @property (assign, nonatomic) id<TouchViewDelegate> delegate;

 @end

 //

 //  TouchView.m

 //  LessonUIControlAndSubClass

 //

 #import "TouchView.h"

 @implementation TouchView

 //3.一旦找到代理，让代理执行事情

 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

     //判断delegate是否实现了某方法

     if ([_delegate respondsToSelector:@selector(touchBegan:)]) {

         [_delegate touchBegan:self];

     }

 }

 - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {

     if ([_delegate respondsToSelector:@selector(touchMoved:)]) {

         [_delegate touchMoved:self];

     }

 }

 - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {

     if ([_delegate respondsToSelector:@selector(touchEnded:)]) {

         [_delegate touchEnded:self];

     }

 }

 - (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event {

     if ([_delegate respondsToSelector:@selector(touchCancelled:)]) {

         [_delegate touchCancelled:self];

     }

 }

 @end