RAC_4.常用用法

4.常用用法

4.1 代替代理

    JJView *view = [[JJView alloc]init];
    view.backgroundColor = [UIColor yellowColor];
    view.frame = CGRectMake(10, 64, 400, 500);
    [self.view addSubview:view];
    RACSignal *signal = [view rac_signalForSelector:@selector(didClickButton:)];
    [signal subscribeNext:^(RACTuple *  _Nullable x) {
        NSLog(@"%@",x);
        [x.rac_sequence.signal subscribeNext:^(id  _Nullable x) {
            if ([x isKindOfClass:[UIButton class]]) {
                UIButton *btn = (UIButton *)x;
                dispatch_async(dispatch_get_main_queue(), ^{
                    self.view.backgroundColor = btn.backgroundColor;
                });
                
            }
        }];

    }];

4.2 代替KVO

首先在这里我们要监听self.view的frame属性值的变化

    JJView *view = [[JJView alloc]init];
    view.backgroundColor = [UIColor yellowColor];
    view.frame = CGRectMake(10, 64, 100, 100);
    [self.view addSubview:view];
    
    [view rac_observeKeyPath:@"frame" options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld observer:nil block:^(id value, NSDictionary *change, BOOL causedByDealloc, BOOL affectedOnlyLastComponent) {
        //回调
        NSLog(@"value%@---%@",value,change);
    }];
    self.view = view;

touchesBegan:方法

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    static int x = 50;
    x++;
    self.view.frame = CGRectMake(x, 64, 200, 200);
}

运行如图：

image

更简便的方法

    JJView *view = [[JJView alloc]init];
    view.backgroundColor = [UIColor yellowColor];
    view.frame = CGRectMake(10, 64, 100, 100);
    [self.view addSubview:view];
    self.view = view;
   RACSignal *signal = [view rac_valuesForKeyPath:@"frame" observer:nil];
    [signal subscribeNext:^(id  _Nullable x) {
        NSLog(@"%@",x);
    }];

运行如下图：

image

4.3 监听

• 监听UIButton

    UIButton *btn = [[UIButton alloc]initWithFrame:CGRectMake(10, 100, 100, 50)];
    [self.view addSubview:btn];
    [btn setBackgroundColor:[UIColor blackColor]];
    [btn setTitle:@"点点" forState:UIControlStateNormal];
    RACSignal *signal = [btn rac_signalForControlEvents:(UIControlEventTouchUpInside)];
    [signal subscribeNext:^(id  _Nullable x) {
        NSLog(@"%@",x);
    }];

• 监听UITextField

    UITextField *textField = [[UITextField alloc]initWithFrame:CGRectMake(10, 100, 100, 50)];
    textField.backgroundColor = [UIColor blueColor];
    [self.view addSubview:textField];
    
    [textField.rac_textSignal subscribeNext:^(NSString * _Nullable x) {
        NSLog(@"%@",x);
        
    }];

运行如下：

image

4.4 代替通知

[[[NSNotificationCenter defaultCenter] rac_addObserverForName:UIKeyboardWillShowNotification object:nil] subscribeNext:^(NSNotification * _Nullable x) {
        NSLog(@"%@",x);
    }];

运行如下

image

4.5 代替NSTimer

在我们以往使用NSTimer 做定时循环执行的时候，

[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timerMethod) userInfo:nil repeats:YES];

正常情况下运行

image

大家有没有遇到过，如果timerMethod正在执行，而此时如果有UI事件的触发，比如滚动我们的屏幕，我们timerMethod执行将会被暂停执行，一旦UI事件执行完毕，timerMethod又会开始执行。原因是我们的NSTimer的事件是交给Runloop去处理，那么Runloop在执行的时候UI模式具有最高优先权。
那要解决这种问题怎么办呢？大家可能会想到，把他放到子线程中去执行， 开启runloop循环。

• 解决方式①——开启runloop循环

    if (@available(iOS 10.0, *)) {
        NSThread * thread = [[NSThread alloc]initWithBlock:^{
            NSTimer * timer = [NSTimer timerWithTimeInterval:1.0 target:self selector:@selector(timerMethod) userInfo:nil repeats:YES];
            //Runloop模式 && 多线程!!
            //NSDefaultRunLoopMode 默认模式;
            //UITrackingRunLoopMode UI模式:只能被UI事件唤醒!!
            //NSRunLoopCommonModes  占位模式:默认&UI模式
            [[NSRunLoop currentRunLoop] addTimer:timer forMode:NSRunLoopCommonModes];
            
            //开启runloop循环
            [[NSRunLoop currentRunLoop] run];
        }];
        [thread start];
    } else {
        // Fallback on earlier versions
    }

• 解决方式②——GCD设置timer

    //GCD设置timer
    dispatch_source_t timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, dispatch_get_global_queue(0, 0));
    //GCD的事件单位是纳秒
    dispatch_source_set_timer(timer, DISPATCH_TIME_NOW, 1.0 * NSEC_PER_SEC, 0);
    dispatch_source_set_event_handler(timer, ^{
        NSLog(@"我是timer");
        NSLog(@"-----_%@",[NSThread currentThread]);
    });
    //启动
    dispatch_resume(timer);
    _timer = timer;

• 解决方式③——RAC

@interface CommonUseViewControllerr ()
@property(nonatomic,strong)RACDisposable  * timerDisposable;
@end

@implementation CommonUseViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    _timerDisposable = [[RACSignal interval:1.0 onScheduler:[RACScheduler scheduler]] subscribeNext:^(NSDate * _Nullable x) {
        NSLog(@"%@",[NSThread currentThread]);
    }];
}
-(void)dealloc{
    //取消订阅!!
    [_timerDisposable dispose];
}
@end

倒计时🌰

@interface CommonUseViewController ()

@property(assign,nonatomic)int time;
/**   */
@property(nonatomic,strong)RACDisposable  * disposable;
/**   */
@property(nonatomic,strong)RACSignal * signal;
@end

 UIButton *btn = [[UIButton alloc]initWithFrame:CGRectMake(10, 64, 100, 50)];
    [btn setBackgroundColor:[UIColor blueColor]];
    [self.view addSubview:btn];
    [btn setTitle:@"发送验证码" forState:UIControlStateNormal];
    RACSignal *signal = [btn rac_signalForControlEvents:(UIControlEventTouchUpInside)];
    [signal subscribeNext:^(UIButton *  btn) {
        NSLog(@"%@",btn);
        btn.enabled = NO;
        //设置倒计时
        self.time = 10;
        //每一秒进来
        self.signal = [RACSignal interval:1.0 onScheduler:[RACScheduler mainThreadScheduler]];
        
        self.disposable = [self.signal subscribeNext:^(NSDate * _Nullable x) {
            NSLog(@"%@",self);
            //时间先减少!
            _time--;
            //设置文字
            NSString * btnText = _time > 0 ? [NSString stringWithFormat:@"请等待%d秒",_time]
            : @"重新发送";
            [btn setTitle:btnText forState:_time > 0?(UIControlStateDisabled):(UIControlStateNormal)];
            //设置按钮
            if(_time > 0){
                btn.enabled = NO;
            }else{
                btn.enabled = YES;
                //取消订阅!!
                [_disposable dispose];
            }
        }];
    }];