UI基础整理--18

通知

#import "ThirdViewController.h"

#import "SettingViewController.h"

//注册一个通知

        //通过单例的方式获取通知中心对象

        //第一个参数:收到通知后谁负责执行方法

        //第二个参数:执行的方法

        //第三个参数:通知中心的名字,用于移除或者收到通知的标志

        //第四个参数:参数对象,可以为nil

        [[NSNotificationCenterdefaultCenter]addObserver:selfselector:@selector(changeTheme:)name:@"Theme"object:nil];

//收到广播后执行的方法,参数为NSNotification(通知)

- (void)changeTheme:(NSNotification *)notification{

    

    //接收通知发送的消息(以字典方式存储)

    NSDictionary *dict = notification.userInfo;

    //获取字典中的值,并作出相应的修改

    self.view.backgroundColor = dict[@"color"];

    

}

//

//  SettingViewController.m

//  Lesson_NotificationCenter

//

//  Created by Floating_SH on 15/12/12.

//  Copyright © 2015年 SH. All rights reserved.

//

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{

    //广播通知

    [[NSNotificationCenterdefaultCenter]postNotificationName:@"Theme"object:niluserInfo:@{@"color" : [UIColorgreenColor]}];

    

    [selfdismissViewControllerAnimated:YEScompletion:nil];

}

观察者

//

//  ViewController.m

//  Lession18_观察者

//

//  Created by Floating_SH on 15/12/11.

//  Copyright © 2015年 SH. All rights reserved.

//

#import "ViewController.h"

#import "SingleVip.h"

@interface ViewController ()

@property (nonnull,strong)SingleVip * vip;

@end

@implementation ViewController

- (void)viewDidLoad {

    [superviewDidLoad];

    

    //KVO

    self.vip = [SingleVipnew];

    

    self.vip.name =@"王静文";

    

    //void *   指空类型   context  能传递任何值

    [self.vipaddObserver:selfforKeyPath:@"name"options:NSKeyValueObservingOptionNewcontext:(__bridgevoid * _Nullable)(self)];

    

    

}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{

    

    self.vip.name =@"王菲";

}

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> *)change context:(void *)context{

    

    //被观察对象的属性

    NSLog(@"keyPath == %@",keyPath);

    //被观察的对象(self.vip)

    NSLog(@"object == %@",object);

    //字典

    NSLog(@"%@",change[@"new"]);

    //辅助传递过来的值

    ViewController *vc = (__bridgeViewController *)(context);

    vc.view.backgroundColor = [UIColoryellowColor];

    NSLog(@"context == %@",context);

    

}

- (void)didReceiveMemoryWarning {

    [superdidReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

}

@end