RAC实践3 --- 代替OC实现

1.监听已经存在的方法：

    RACSignal *signal = [self rac_signalForSelector: @selector(viewWillAppear:)];
    
    [signal subscribeNext:^(id  _Nullable x) {
        NSLog(@"监听到了");
    }];

---

2.替换delegate：

方式一：使用rac_signalForSelector：fromProtocol:

                  //以下代码是在controller中

    NewView *newView = [[NewView alloc] initWithFrame: CGRectMake(10, 10, 100, 110)];
    [self.view addSubview: newView];
    
    RACSignal *signal = [self rac_signalForSelector: @selector(protocolMethod) fromProtocol: @protocol(NewViewDelegate)];
    [signal subscribeNext:^(id  _Nullable x) {
        NSLog(@"监听到了");
    }];
    
    //最后设置代理
    newView.delegate = self;

方式二：使用RACSubject

//在添加delegate的.h文件中：
@interface NewView : UIView
@property (strong, nonatomic) RACSubject *subject;
@end

//.m文件中：
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    //代理回调的地方
    if (self.subject) {
        [self.subject sendNext: @"haha"];
    }
}

//controller需要被回调的地方
    NewView *newView = [[NewView alloc] initWithFrame: CGRectMake(10, 10, 100, 110)];
    [self.view addSubview: newView];
        
    newView.subject = [[RACSubject alloc] init];
    
    [newView.subject subscribeNext:^(id  _Nullable x) {
        NSLog(@" ~~~ %@",x);
    }];

---

3.替换监听、KVO

监听UITextField输入事件：

    [[self.uidTF rac_textSignal] subscribeNext:^(NSString * _Nullable x) {
        NSLog(@"%@",x);
    }];

替换系统kvo方式1：

    [RACObserve(self.uidTF, text) subscribeNext:^(id  _Nullable x) {
        NSLog(@"observe :%@",x);
    }];

替换系统kvo方式2：

    //需要导入头文件 #import 

    [self.view rac_observeKeyPath: @"frame"
                          options: NSKeyValueObservingOptionOld | NSKeyValueObservingOptionNew
                         observer: self
                            block:^(id value, NSDictionary *change, BOOL causedByDealloc, BOOL affectedOnlyLastComponent) {
        
    }];

---

4.替换UIButton事件

    UIButton *btn = [UIButton new];
    
    [[btn rac_signalForControlEvents: UIControlEventTouchUpInside] subscribeNext:^(__kindof UIControl * _Nullable x) {
        
    }];

---

5.替换通知NSNotification

    [[[NSNotificationCenter defaultCenter] rac_addObserverForName: UIKeyboardDidHideNotification object: nil] subscribeNext:^(NSNotification * _Nullable x) {
        
    }];

---

6.替换定时器

   __block NSInteger i = 10;
    self.timerDisposable = [[RACSignal interval: 1 onScheduler: [RACScheduler mainThreadScheduler]] subscribeNext:^(NSDate * _Nullable x) {
        i --;
        if (i <= 0) {
            [self.timerDisposable dispose];
        }
    }];