IOS中delegate的使用方法

写了一个简单的委托的试用测试：

首先创建FunctionTest类，声明委托：

FunctionTest.h

//
//  FunctionTest.h
//  DelegateDemo
//
//  Created by shx on 12-7-17.
//  Copyright (c) 2012年 __MyCompanyName__. All rights reserved.
//

#import <Foundation/Foundation.h>

@protocol FunctionTestDelegate;

@interface FunctionTest : NSObject
{
    id<FunctionTestDelegate> delegate;
}
@property (nonatomic, assign)id<FunctionTestDelegate> delegate;
- (void)func1;
- (void)func2;
@end

@protocol FunctionTestDelegate <NSObject>

- (void)func3;
- (void)func4;

@end

FunctionTest.m

//
//  FunctionTest.m
//  DelegateDemo
//
//  Created by shx on 12-7-17.
//  Copyright (c) 2012年 __MyCompanyName__. All rights reserved.
//

#import "FunctionTest.h"

@implementation FunctionTest

@synthesize delegate;

- (void)func1
{
    NSLog(@"function 1 called...");
    [delegate performSelector:@selector(func3)];
}

- (void)func2
{
    NSLog(@"function 2 called...");
    [delegate performSelector:@selector(func4)];
}
@end

在appdelegate中实现委托：

//
//  AppDelegate.h
//  DelegateDemo
//
//  Created by shx on 12-7-17.
//  Copyright (c) 2012年 __MyCompanyName__. All rights reserved.
//

#import <UIKit/UIKit.h>
#import "FunctionTest.h"

@class ViewController;

@interface AppDelegate : UIResponder <UIApplicationDelegate,FunctionTestDelegate>
{
    FunctionTest *test;
}

@property (strong, nonatomic) UIWindow *window;

@property (strong, nonatomic) ViewController *viewController;

@end

AppDelegate.m中实现：

#pragma mark -FunctionTestDelegate
- (void)func3
{
    NSLog(@"function 3 called...ns");
}
- (void)func4
{
    NSLog(@"function 4 called...ns");
}

在

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

调用添加：

test = [[FunctionTest alloc]init];
    test.delegate = self;

    [test func1];
    [test func2];

到这里，delegate就写完了。