delegate的练习

//在RootViewController.h里面遵守协议

#import <UIKit/UIKit.h>

@interface RootViewController : UIViewController

@end

-----------------------------------<>-------------------------

//RootViewController.m

#import "RootViewController.h"

#import "TouchView.h"

@interface RootViewController ()<TouchViewDelegate>{

TouchView *touch;

}

@end

@implementation RootViewController

- (void)viewDidLoad {

[super viewDidLoad];

touch = [[TouchView alloc] initWithFrame:CGRectMake(10, 65, 100, 100)];

touch.backgroundColor = [UIColor redColor];

touch.delegate = self;

[self.view addSubview:touch];

[touch release];

}

- (void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

#pragma mark - TouchViewDelegate

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

touch.backgroundColor = [UIColor colorWithRed:arc4random() % 256 / 255. green:arc4random() % 256 / 255. blue:arc4random() % 256 / 255. alpha:1.0];

}

@end

----------------------------<自己定义的TouchView, 继承于UIView>-----------------------------

#import <UIKit/UIKit.h>

@protocol TouchViewDelegate <NSObject>//制订协议, 协议名 : 类名 + delegate

-(void)canTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event;//制定协议里面的方法

@end

@interface TouchView : UIView

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

@end

----------------------------------------------<>-------------------------------------------

#import "TouchView.h"

@implementation TouchView

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

//让代理执行本应该TouchView完成的方法

if ([_delegate respondsToSelector:@selector(canTouchesEnded:withEvent:)]) {

[_delegate canTouchesEnded:touches withEvent:event];//把参数传进来

}

//    self.backgroundColor = [UIColor colorWithRed:arc4random() % 256 / 255. green:arc4random() % 256 / 255. blue:arc4random() % 256 / 255. alpha:1.0];

}

@end