1、常见用法
1、代替代理
2、代替KVO
3、监听事件
4、代替通知
5、监听文本框
2、RAC代替代理
在OC中我们什么情况下会用到代理？一般会在多控制器传值或者自定义View的点击事件传递等
首先我们自定义一个View并在View中添加一个按钮，当按钮点击的时候如何传值？
-------------------- JMView.h --------------------
//
// JMView.h
// RAC常见用法
//
// Created by JM on 2018/4/21.
// Copyright © 2018年 JM. All rights reserved.
//
#import <UIKit/UIKit.h>
@interface JMView : UIView
@end
-------------------- JMView.m --------------------
//
// JMView.m
// RAC常见用法
//
// Created by JM on 2018/4/21.
// Copyright © 2018年 JM. All rights reserved.
//
#import "JMView.h"
@implementation JMView
- (instancetype)initWithFrame:(CGRect)frame {
if (self = [super initWithFrame:frame]) {
UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
[btn setTitle:@"点我" forState:UIControlStateNormal];
[btn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
btn.backgroundColor = [UIColor orangeColor];
btn.frame = CGRectMake(10, 10, 100, 50);
//按钮的点击事件
[btn addTarget:self action:@selector(btnClick) forControlEvents:UIControlEventTouchUpInside];
[self addSubview:btn];
}
return self;
}
- (void)btnClick {
[self lailma:@"666"];
}
- (void)lailma:(NSString *)str {
}
@end
控制器中直接监听自定义View的点击事件
[[self.jmView rac_signalForSelector:@selector(lailma:)] subscribeNext:^(RACTuple * _Nullable x) {
NSLog(@"按钮被点击了----%@", x);
}];
3、RAC代替KVO
我们都知道kvo的特性是当监听属性的值变化的时候就会走进observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context，那么如何用RAC实现呢！下面我们来监听自定义View的frame，当frame值变化的时候我们就走进自定义方法
控制器监听自定义View的frame，当我们点击屏幕的时候改变自定义View的frame，看在
subscribeNext能不能监听到值的改变
//
// ViewController.m
// RAC常见用法
//
// Created by JM on 2018/4/21.
// Copyright © 2018年 JM. All rights reserved.
//
#import "ViewController.h"
#import "JMView.h"
#import <ReactiveObjC/ReactiveObjC.h>
#import <ReactiveObjC/NSObject+RACKVOWrapper.h>
//#import <NSObject+RACKVOWrapper.h>
@interface ViewController ()
/** jmView */
@property (nonatomic, strong) JMView *jmView;
@end
@implementation ViewController
- (JMView *)jmView {
if (!_jmView) {
_jmView = [[JMView alloc] initWithFrame:CGRectMake(10, 100, 300, 100)];
_jmView.backgroundColor = [UIColor purpleColor];
[self.view addSubview:_jmView];
}
return _jmView;
}
- (void)viewDidLoad {
[super viewDidLoad];
//RACKVO监听自定义view的frame方式1
[[self.jmView rac_valuesForKeyPath:@"frame" observer:nil] subscribeNext:^(id _Nullable x) {
NSLog(@"%@",x);
}];
// //RACKVO监听自定义view的frame方式2
// self.jmView rac_observeKeyPath:@"frame" options:NSKeyValueObservingOptionOld | [NSKeyValueChangeNewKey observer:nil block:^(id value, NSDictionary *change, BOOL causedByDealloc, BOOL affectedOnlyLastComponent) {
// NSLog(@"%@---%@",value, change);
// }];
}
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
self.jmView.frame = CGRectMake(10, 100, 310, 120);
}
@end
控制台输出结果
2018-04-21 16:44:40.993034+0800 RAC常见用法[45086:1889455] NSRect: {{10, 100}, {300, 100}}
2018-04-21 16:44:44.682167+0800 RAC常见用法[45086:1889455] NSRect: {{10, 100}, {310, 120}}
4、RAC监听事件
首先我们在控制器中创建一个按钮，用OC原生的方式使用addTarget: action: forControlEvents: 的方式，用RAC如何写？
//
// ViewController.m
// RAC常见用法
//
// Created by JM on 2018/4/21.
// Copyright © 2018年 JM. All rights reserved.
//
#import "ViewController.h"
#import "JMView.h"
#import <ReactiveObjC/ReactiveObjC.h>
#import <ReactiveObjC/NSObject+RACKVOWrapper.h>
//#import <NSObject+RACKVOWrapper.h>
@interface ViewController ()
/** btn */
@property (nonatomic, strong) UIButton *btn;
@end
@implementation ViewController
- (UIButton *)btn {
if (!_btn) {
_btn = [UIButton buttonWithType:UIButtonTypeCustom];
_btn.backgroundColor = [UIColor orangeColor];
[_btn setTitle:@"我是按钮" forState:UIControlStateNormal];
[_btn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
_btn.frame = CGRectMake(50, 100, 100, 50);
[self.view addSubview:_btn];
}
return _btn;
}
- (void)viewDidLoad {
[super viewDidLoad];
//监听事件(OC原生写法)
// [self.btn addTarget:self action:@selector(btnClick) forControlEvents:UIControlEventTouchUpInside];
//监听事件(RAC写法)
[[self.btn rac_signalForControlEvents:UIControlEventTouchUpInside] subscribeNext:^(__kindof UIControl * _Nullable x) {
NSLog(@"按钮被点击了---%@", x);
}];
}
@end
控制器中输出并把当前的事件对象打印出来
2018-04-21 18:30:24.529704+0800 RAC常见用法[47170:1969057] 按钮被点击了---<UIButton: 0x7fee62e143c0; frame = (50 100; 100 50); opaque = NO; layer = <CALayer: 0x600000023820>>
5、RAC代替通知
用原声OC监听通知的时候使用addObserver: selector: name: object:];来监听通知并实现selector方法，通知使用完毕后还需销毁通知，但是RAC一行代码即可实现监听通知并且内置机制会自动销毁通知。
//原生OC监听通知
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(changeEvent) name:@"evnet" object:nil];
//RAC监听通知
[[[NSNotificationCenter defaultCenter] rac_addObserverForName:@"event" object:nil] subscribeNext:^(NSNotification * _Nullable x) {
NSLog(@"%@",x);
}];
6、RAC监听文本框
首先我们在控制器声明一个UITextFiled，如果用原生OC写法想实时监听输入框的值，有两种写法，1、遵守代理、实现代理。2、给输入框添加一个改变事件的方法。上述两种都比较麻烦，如果用RAC来实现那就显然要简单的多了。
//
// ViewController.m
// RAC常见用法
//
// Created by JM on 2018/4/21.
// Copyright © 2018年 JM. All rights reserved.
//
#import "ViewController.h"
#import "JMView.h"
#import <ReactiveObjC/ReactiveObjC.h>
#import <ReactiveObjC/NSObject+RACKVOWrapper.h>
//#import <NSObject+RACKVOWrapper.h>
@interface ViewController ()
/** tf */
@property (nonatomic, strong) UITextField *tf;
@end
@implementation ViewController
- (UITextField *)tf {
if (!_tf) {
_tf = [[UITextField alloc] initWithFrame:CGRectMake(50, 100, 200, 40)];
_tf.borderStyle = UITextBorderStyleRoundedRect;
[self.view addSubview:_tf];
}
return _tf;
}
- (void)viewDidLoad {
[super viewDidLoad];
//RAC实时监听输入框的值
[self.tf.rac_textSignal subscribeNext:^(NSString * _Nullable x) {
NSLog(@"%@",x);
}];
@end
控制台打印结果
2018-04-21 18:44:11.775392+0800 RAC常见用法[47518:1991465] 1
2018-04-21 18:44:12.069070+0800 RAC常见用法[47518:1991465] 12
2018-04-21 18:44:12.589818+0800 RAC常见用法[47518:1991465] 123
2018-04-21 18:44:12.784590+0800 RAC常见用法[47518:1991465] 1233
2018-04-21 18:44:12.992636+0800 RAC常见用法[47518:1991465] 12331
2018-04-21 18:44:13.116296+0800 RAC常见用法[47518:1991465] 123314
2018-04-21 18:44:13.302748+0800 RAC常见用法[47518:1991465] 1233141
2018-04-21 18:44:14.850617+0800 RAC常见用法[47518:1991465] 123314
2018-04-21 18:44:15.113347+0800 RAC常见用法[47518:1991465] 12331
2018-04-21 18:44:15.270610+0800 RAC常见用法[47518:1991465] 1233
2018-04-21 18:44:15.422058+0800 RAC常见用法[47518:1991465] 12336
2018-04-21 18:44:15.579953+0800 RAC常见用法[47518:1991465] 123366
2018-04-21 18:44:15.746990+0800 RAC常见用法[47518:1991465] 1233666
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