iOS开发ReactiveCocoa学习笔记(三)

RAC常用用法:

1.监听按钮的点击事件:

 UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    button.frame = CGRectMake(100, 100, 80, 40);
    [button setTitle:@"点击事件" forState:UIControlStateNormal];
    [button setBackgroundColor:[UIColor redColor]];
    [self.view addSubview:button];
    
    [[button rac_signalForControlEvents:UIControlEventTouchUpInside] subscribeNext:^(id x) {
        NSLog(@"按钮被点击了");
    }];

2.代理的使用:

@interface RedView : UIView

//*  */
@property (nonatomic, strong) RACSubject *btnClickSignal;

@end

#import "RedView.h"

@implementation RedView
- (void)awakeFromNib {

    [super awakeFromNib];
}

//懒加载信号
- (RACSubject *)btnClickSignal {

    if (_btnClickSignal == nil) {
        _btnClickSignal = [RACSubject subject];
    }
    return _btnClickSignal;
}

- (IBAction)btnClick:(UIButton *)sender {
    
    [self.btnClickSignal sendNext:@"按钮被点击了"];
}

@end

 // 只要传值,就必须使用RACSubject
    RedView *redView = [[[NSBundle mainBundle] loadNibNamed:@"RedView" owner:nil options:nil] lastObject];
    redView.frame = CGRectMake(0, 140, self.view.bounds.size.width, 200);
    [self.view addSubview:redView];
    [redView.btnClickSignal subscribeNext:^(id x) {
        NSLog(@"---点击按钮了,触发了事件");
    }];
    
    // 把控制器调用didReceiveMemoryWarning转换成信号
    //rac_signalForSelector:监听某对象有没有调用某方法

    [[self rac_signalForSelector:@selector(didReceiveMemoryWarning)] subscribeNext:^(id x) {
        NSLog(@"控制器调用didReceiveMemoryWarning");

    }];

3.KVO

把监听redV的center属性改变转换成信号，只要值改变就会发送信号

 // observer:可以传入nil
    [[redView rac_valuesAndChangesForKeyPath:@"center" options:NSKeyValueObservingOptionNew observer:nil] subscribeNext:^(id x) {
        NSLog(@"center:%@",x);
    }];

4.代替通知

UITextField *textfield = [[UITextField alloc] initWithFrame:CGRectMake(100, 340, 150, 40)];
    textfield.placeholder = @"监听键盘的弹起";
    textfield.borderStyle = UITextBorderStyleRoundedRect;
    [self.view addSubview:textfield];
    
    [[[NSNotificationCenter defaultCenter] rac_addObserverForName:UIKeyboardWillShowNotification object:nil] subscribeNext:^(id x) {
        NSLog(@"监听键盘的高度:%@",x);
    }];
    

5.监听文字的改变

   [textfield.rac_textSignal subscribeNext:^(id x) {
       
        NSLog(@"输入框中文字改变了---%@",x);
    }];
    

6.处理多个请求，都返回结果的时候，统一做处理.

 RACSignal *request1 = [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
        
        // 发送请求1
        [subscriber sendNext:@"发送请求1"];
        return nil;
    }];
    
    RACSignal *request2 = [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
        // 发送请求2
        [subscriber sendNext:@"发送请求2"];
        return nil;
    }];
    
    // 使用注意：几个信号，参数一的方法就几个参数，每个参数对应信号发出的数据。
    [self rac_liftSelector:@selector(updateUIWithR1:r2:) withSignalsFromArray:@[request1,request2]];


// 更新UI
- (void)updateUIWithR1:(id)data r2:(id)data1
{
    NSLog(@"更新UI%@  %@",data,data1);
}