RAC 前篇--给Button 添加Block回调

Button是我们最常见的控件了下面看下常规用法

- (void)viewDidLoad { 

    [super viewDidLoad];

    [self createView];

    // Do any additional setup after loading the view.

}

- (void)createView{

  UIButton * mybutton = [UIButton buttonWithType:UIButtonTypeCustom];

    mybutton.frame=CGRectMake(50,300,40,20);

    [mybutton setTitle:@"test" forState:UIControlStateNormal];

    [mybutton setBackgroundColor:[UIColor orangeColor]];

    [mybutton addTarget:self action:@selector(dealButtonAction:) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:mybutton];

}
//button点击事件
-(void)dealButtonAction:(UIButton*)bu{

    NSLog(@"处理点击事件");

}

每一个Button 都要对应一个对应的方法,如果有十个八个button的话那么创建十个八个方法的话,那的多乱,多么的难找
细想一下.如果Button 能这样

    [mybutton addEventHandler:^{
         NSLog(@"处理点击事件");
    } forControlEvents:UIControlEventTouchUpInside];

是不是很神奇

那怎么才能办到呢

1. button 添加了方法要用到分类
2. button 新方法进行了事件绑定用到了RunTimes
   话不多说 上代码

#import <UIKit/UIKit.h>
#import <objc/runtime.h>
/** 事件回调的block */
typedef void (^UIButtonBlock) (void);

NS_ASSUME_NONNULL_BEGIN

@interface UIButton (block)

@property (nonatomic,copy)UIButtonBlock   touchAction;

- (void)addEventHandler:(void (^)(void))block forControlEvents:(UIControlEvents)controlEvents;

@end

//------- 漂亮的分割线 -------//

#import "UIButton+block.h"
@implementation UIButton (block)
//------- 添加属性 -------//
static void *touchActionKey = &touchActionKey;
- (UIButtonBlock)touchAction{
    return objc_getAssociatedObject(self, &touchActionKey);
}
- (void)setTouchAction:(UIButtonBlock)touchAction{
    objc_setAssociatedObject(self, &touchActionKey, touchAction, OBJC_ASSOCIATION_COPY);
}
/**
 给按钮绑定事件回调block
 @param block 回调的block
 @param controlEvents 回调block的事件
 */
- (void)addEventHandler:(void (^)(void))block forControlEvents:(UIControlEvents)controlEvents {
    self.touchAction = block;
    [self addTarget:self action:@selector(blcokButtonClicked) forControlEvents:controlEvents];
}
// 按钮点击
- (void)blcokButtonClicked {
    if (self.touchAction) {
        self.touchAction();
    }
}

button扩展了一个带block回调的方法,然后绑定了对应的事件,就是有点复杂.
是不是很神奇 , 如果你感觉这样很好玩,那么下面的一个叫RAC的东西,更方便更高效

pod导入

pod 'ReactiveObjC', '~> 3.0.0'

头文件

#import <ReactiveObjC.h>

开始用

   [[mybutton rac_signalForControlEvents:UIControlEventTouchUpInside] subscribeNext:^(__kindof UIControl * _Nullable x) {
        NSLog(@"处理点击事件");
    }];

是不是很简洁,那么下面请看

RAC初探