自定義通知

1、獲得通知中心對象

NSNotificationCenter  *center= [NSNotificationCenter defaultCenter];  //單例實際事獲得通知中心的地址

2、監聽通知

[center addObserver :監聽者 selector：須執行的方法 name：所監聽者通知的名稱 object：通知發送者];

3、通知中心發布消息

[center PostNotificationName：@"為人民服務" object：某人]；

4.移除監聽中心

[center removeObserver:self name:@"為人民服務" object:某人];

創建King、Worker、Farmer類，由King發一個自定義通知，Worker和Farmer類監聽通知，通知內容為打印“某某為人民服務”。

#import <Foundation/Foundation.h>

@interface King : NSObject

-(void)senfMessage;//創建并發送通知

@end

#import "King.h"

@implementation King

-(void)senfMessage{

//創建通知對象,通知的名字是MESSAGE

NSNotification *notification = nil;

   notification = [NSNotificationnotificationWithName:@"MESSAGE"object:selfuserInfo:nil];

//發送通知

   [[NSNotificationCenterdefaultCenter] postNotification:notification];

NSLog(@"我是國王,我正在給我的子民發送通知");

}

@end

#import <Foundation/Foundation.h>

@interface Worker : NSObject

@property(retain,nonatomic) NSString *name;

-(void)say:(NSNotification *) notif;//收到通知后要做的事

@end

#import "Worker.h"

@implementation Worker

-(id)init{

if (self = [superinit]) {

//注冊監聽者

       [[NSNotificationCenterdefaultCenter] addObserver:selfselector:@selector(say:) name:@"MESSAGE"object:nil];

       }

returnself;

}

-(void)say:(NSNotification *) notif{//收到通知后要做的事

Worker *wk = [[Workeralloc] init];

   wk.name = @"小麥";

NSLog(@"工人%@說我要為人民服務",wk.name);

   [wk release];

}

-(void)dealloc{//移除通知

   [[NSNotificationCenterdefaultCenter] removeObserver:selfname:@"MESSAGE"object:nil];

   [superdealloc];

}

@end

#import <Foundation/Foundation.h>

@interface Farmer : NSObject

@property(retain,nonatomic) NSString *name;

-(void)say:(NSNotification *) notif;//收到通知后要做的事

@end

#import "Farmer.h"

@implementation Farmer

-(id)init{

if (self = [superinit]) {

//注冊監聽者

       [[NSNotificationCenterdefaultCenter] addObserver:selfselector:@selector(say:) name:@"MESSAGE"object:nil];

   }

returnself;

}

-(void)say:(NSNotification *) notif{//收到通知后要做的事

Farmer *fa = [[Farmeralloc] init];

   fa.name = @"小明";

NSLog(@"農民%@說我要為人民服務",fa.name);

   [fa release];

}

-(void)dealloc{//移除通知

   [[NSNotificationCenterdefaultCenter] removeObserver:selfname:@"MESSAGE"object:nil];

   [superdealloc];

}

@end

#import <Foundation/Foundation.h>

#import "King.h"

#import "Worker.h"

#import "Farmer.h"

int main(int argc, constchar * argv[])

{

@autoreleasepool {

//對象初始化

Worker *w = [[Workeralloc]init];

Farmer *f = [[Farmeralloc]init];

King *k = [[Kingalloc]init];

       [k senfMessage];//創建并發送通知

       [k release];

       [w release];

       [f release];

   }

return 0;

}