[消息传递之一]－NSNotification练习

ゞ浴缸里的玫瑰 2022-08-18 14:22 167阅读 0赞

#import <UIKit/UIKit.h>
    
    @interface ViewController : UIViewController
    
    
    - (IBAction)RegisterNot:(UIButton *)sender;
    - (IBAction)ExecuteNot:(UIButton *)sender;
    - (IBAction)RemoveNot:(UIButton *)sender;
    
    //注意点1:响应通知中心的函数为固定格式，如果需要参数的话，需要解析。
    -(void)ExcuteNotification:(NSNotification*) aNotification;
    @end

#import "ViewController.h"
    
    @interface ViewController ()
    
    @end
    
    @implementation ViewController
    {
        NSNotificationCenter* m_NC;
    }
    - (void)viewDidLoad {
        m_NC = [NSNotificationCenter defaultCenter];
        [super viewDidLoad];
        // Do any additional setup after loading the view, typically from a nib.
    }
    
    - (void)didReceiveMemoryWarning {
        [super didReceiveMemoryWarning];
        // Dispose of any resources that can be recreated.
    }
    
    - (IBAction)RegisterNot:(UIButton *)sender {
        
        //注意点2:注册观察者的name和调用的name必须一样。最晚在self析构的时候，删除观察者。可重复。
        [m_NC addObserver:self selector:@selector(ExcuteNotification:) name:@"notifi" object:nil];
    }
    
    - (IBAction)ExecuteNot:(UIButton *)sender{
        //注意点3:object参数可传可不传,取决于接收者的使用
        //[m_NC postNotificationName:@"notifi" object:@"hello"];
        //注意点4:在哪个线程执行的post就用哪个线程执行。
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
            NSDictionary* ds =[NSDictionary dictionaryWithObject:@"value" forKey:@"key"];
            [m_NC postNotificationName:@"notifi" object:@"obj" userInfo:ds];
        });
    }
    
    - (IBAction)RemoveNot:(UIButton *)sender {
        [m_NC removeObserver:self];
    }
    
    -(void)ExcuteNotification:(NSNotification*) aNotification
    {
        NSString* rds = [[aNotification userInfo] objectForKey:@"key"];
        NSLog(@"来自通知中心的消息，对象：%@,参数：%@",[aNotification object],rds);
        NSLog(@"%@",[NSThread currentThread]);
    }
    @end