iOS 通知notification

ios通知

Notification(单例类)

是一对多的实现，观察者模式

参考如下链接：

http://www.th7.cn/Program/IOS/201406/212434.shtml

举例：

三个页面的跳转：

//页面一

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    //挂出通知change,实现方法为didNotification

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didNotification) name:@"change" object:nil];

    

}

- (void)didNotification{

    self.view.backgroundColor = [UIColor redColor];

}

- (void)didReceiveMemoryWarning {

    

    [super didReceiveMemoryWarning];

}

@end

//页面2

#import "firstPageViewController.h"

@interface firstPageViewController ()

@end

@implementation firstPageViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    //同页面一，挂出通知，实现方法为didChange

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didChange) name:@"change" object:nil];

//    [[NSNotificationCenter defaultCenter] removeObserver:self name:@"change" object:nil];

}

- (void)didChange{

    self.view.backgroundColor = [UIColor greenColor];

}

- (void)didReceiveMemoryWarning {

    [super didReceiveMemoryWarning];

}

@end

//页面3

#import "secondViewController.h"

@interface secondViewController ()

@end

@implementation secondViewController

- (void)viewDidLoad {

    [super viewDidLoad];

}

- (IBAction)didChange:(id)sender {

    //创建一个通知类型对象

    NSNotification *notification = [NSNotification notificationWithName:@"change" object:nil userInfo:nil];

    //使用通知

    [[NSNotificationCenter defaultCenter] postNotification:notification];

}

- (void)didReceiveMemoryWarning {

    [super didReceiveMemoryWarning];

}

@end

storyboard布局见图

当按下第一个页面的button时跳转到页面二，按下页面二的button时跳转到页面三，按下页面三的change按钮，改变相应的背景颜色。

这样可以快速方便的实现多个对象实现统一功能的操作