1、获得通知中心对象
NSNotificationCenter *center= [NSNotificationCenter defaultCenter]; //单例实际事获得通知中心的地址
2、监听通知
[center addObserver :监听者 selector：须执行的方法 name：所监听者通知的名称 object：通知发送者];
3、通知中心发布消息
[center PostNotificationName：@"为人民服务" object：某人]；
4.移除监听中心
[center removeObserver:self name:@"为人民服务" object:某人];
创建King、Worker、Farmer类，由King发一个自定义通知，Worker和Farmer类监听通知，通知内容为打印“某某为人民服务”。
#import <Foundation/Foundation.h>
@interface King : NSObject
-(void)senfMessage;//创建并发送通知
@end
#import "King.h"
@implementation King
-(void)senfMessage{
//创建通知对象,通知的名字是MESSAGE
NSNotification *notification = nil;
notification = [NSNotificationnotificationWithName:@"MESSAGE"object:selfuserInfo:nil];
//发送通知
[[NSNotificationCenterdefaultCenter] postNotification:notification];
NSLog(@"我是国王,我正在给我的子民发送通知");
}
@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]) {
//注册监听者
[[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 = @"小麦";
NSLog(@"工人%@说我要为人民服务",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]) {
//注册监听者
[[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(@"农民%@说我要为人民服务",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 {
//对象初始化
Worker *w = [[Workeralloc]init];
Farmer *f = [[Farmeralloc]init];
King *k = [[Kingalloc]init];
[k senfMessage];//创建并发送通知
[k release];
[w release];
[f release];
}
return 0;
}
