RAC基本用法
2018-01-02 本文已影响39人
CoderLWG
1.信号的创建、订阅和发送
1.1创建信号
RACSignal *signal = [RACSignal createSignal:^RACDisposable * _Nullable(id<RACSubscriber> _Nonnull subscriber) {
NSLog(@"Here I am!");
// 发送信号,在创建信号完成的Block中进行
[subscriber sendNext:@"This is RAC"];
return nil;
}];
1.2 订阅信号
// 订阅信号,这里如果不进行订阅，上面的"Here I am!"也不会执行，订阅到的信号内容就是上面发送的"This is RAC"
[signal subscribeNext:^(id _Nullable x) {
// 信号的内容
NSLog(@"%@",x);
}];
1.3 合并到一块的写法
[[RACSignal createSignal:^RACDisposable * _Nullable(id<RACSubscriber> _Nonnull subscriber) {
NSLog(@"Here I am too!");
// 发送信号
[subscriber sendNext:@"This is RAC too"];
return nil;
}] subscribeNext:^(id _Nullable x) {
// 信号的内容
NSLog(@"%@",x);
}];
2.RAC信号的监听
2.1通知监听
[[[NSNotificationCenter defaultCenter] rac_addObserverForName:UIApplicationDidEnterBackgroundNotification object:nil] subscribeNext:^(NSNotification * _Nullable x) {
NSLog(@"%@",x);
}];
当程序进入后台时，打印
NSConcreteNotification 0x604000259620 {name = UIApplicationDidEnterBackgroundNotification; object = <UIApplication: 0x7f8e546022a0>}
2.2 KVO监听
监听person对象的name属性的改变
self.person = [[Person alloc] init];
self.person.name = @"haha";
[RACObserve(_person, name) subscribeNext:^(id _Nullable x) {
NSLog(@"%@",x);
}];
2.3 监听textField输入
textField输入内容的改变都会通过x打印出来
[[self.textField rac_textSignal] subscribeNext:^(NSString * _Nullable x) {
NSLog(@"%@",x);
}];
3. RAC中循环引用
3.1 OC中传统解决循环引用的方法
/*
OC 传统方法解决循环引用
block 外面 __weak typeof(self) weakSelf = self;
block 里面 __strong typeof(weakSelf) strongSelf = weakSelf;
使用 __unsafe_unretained 來修飾 weakSelf， 如果 self 被釋放的話 那麼 weakSelf 依然會記錄原來的地址 (野指針)
*/
__weak typeof(self) weakSelf = self;
[[self.button rac_signalForControlEvents:UIControlEventTouchUpInside] subscribeNext:^(__kindof UIControl * _Nullable x) {
NSLog(@"%@",x);
// 为了保证block 再传出去 VC 之后被销毁，block仍能正常运行
// strongSelf 是对weakSelf进行了强引用
__strong typeof(weakSelf) strongSelf = weakSelf;
strongSelf.nameLabel.text = @"Hello";
}];
3.2 RAC中解决循环引用的方法
// @weakify(self); 为了打断循环引用，在外面使用@weakify(self)
// @strongify(self); 在block里面使用@strongify(self)
@weakify(self)
[[self.button rac_signalForControlEvents:UIControlEventTouchUpInside] subscribeNext:^(__kindof UIControl * _Nullable x) {
NSLog(@"%@",x);
@strongify(self)
self.nameLabel.text = @"Hello";
}];
4. 联合监听多个控件
// 使用原始方法需要一个一个去监听，使用combineLatest直接把监听对象放进数组中，返回一个元组对象
UITextField *nameTextField = [[UITextField alloc]initWithFrame:CGRectMake(20, 400, 300, 40)];
nameTextField.borderStyle = UITextBorderStyleRoundedRect;
[self.view addSubview:nameTextField];
UITextField *pwdTextField = [[UITextField alloc]initWithFrame:CGRectMake(20, 440, 300, 40)];
pwdTextField.borderStyle = UITextBorderStyleRoundedRect;
[self.view addSubview:pwdTextField];
// [[nameTextField rac_textSignal] subscribeNext:^(NSString * _Nullable x) {
// NSLog(@"%@",x);
// }];
// [[pwdTextField rac_textSignal] subscribeNext:^(NSString * _Nullable x) {
// NSLog(@"%@",x);
// }];
// combineLatest 把多個信號 捆綁成一個信號 最多不要 超過 五個
// RACTuple 元组 它可以像是一個字典，裡面可以放多種類型
[[RACSignal combineLatest:@[nameTextField.rac_textSignal, pwdTextField.rac_textSignal]] subscribeNext:^(RACTuple * _Nullable x) {
// NSLog(@"%@,%@",x,[x class]);
NSString * name = x.first;
NSString * pwd = x.second;
NSLog(@"%@ ,%@", name,pwd);
}];
// id 是一个返回值
// reduce 合并信号的数据，进行汇总计算使用
// 判断用户名和密码同时存在的时候，按钮才能点击！
[[RACSignal combineLatest:@[nameTextField.rac_textSignal, pwdTextField.rac_textSignal] reduce:^id _Nullable(NSString *name, NSString *pwd){
NSLog(@"%@ ,%@", name,pwd);
return @(name.length > 0 && pwd.length > 0);
return nil;
}] subscribeNext:^(id _Nullable x) {
NSLog(@"%@",x);
_button.enabled = [x boolValue];
}];
5. 快速遍历数组和字典
5.1 遍历数组
NSArray *arr = @[@"1",@"2",@"3",@"4",@"5",@"6",@"7"];
// 在数组中遍历元素
for (id obj in arr) {
NSLog(@"%@,%@",obj,[NSThread currentThread]);
}
打印结果：可以看出都是在主线程执行
2018-01-04 16:26:20.092313+0800 MKJMWWM[2703:289030] 1,<NSThread: 0x6000000700c0>{number = 1, name = main}
2018-01-04 16:26:20.092467+0800 MKJMWWM[2703:289030] 2,<NSThread: 0x6000000700c0>{number = 1, name = main}
2018-01-04 16:26:20.092559+0800 MKJMWWM[2703:289030] 3,<NSThread: 0x6000000700c0>{number = 1, name = main}
2018-01-04 16:26:20.092650+0800 MKJMWWM[2703:289030] 4,<NSThread: 0x6000000700c0>{number = 1, name = main}
2018-01-04 16:26:20.092751+0800 MKJMWWM[2703:289030] 5,<NSThread: 0x6000000700c0>{number = 1, name = main}
2018-01-04 16:26:20.092842+0800 MKJMWWM[2703:289030] 6,<NSThread: 0x6000000700c0>{number = 1, name = main}
2018-01-04 16:26:20.092946+0800 MKJMWWM[2703:289030] 7,<NSThread: 0x6000000700c0>{number = 1, name = main}
5.2 数组转换成rac_sequence在进行遍历
[arr.rac_sequence.signal subscribeNext:^(id x) {
NSLog(@"%@,%@",x,[NSThread currentThread]);
} error:^(NSError *error) {
NSLog(@"%@",error);
} completed:^{
NSLog(@"遍历完成了,%@",[NSThread currentThread]);
dispatch_async(dispatch_get_main_queue(), ^{
NSDictionary *dict = @{@"key1":@"111",@"key2":@"222",@"key3":@"333",@"key4":@[@"M",@"K",@"J"]};
[dict.rac_sequence.signal subscribeNext:^(id x) {
// RACTupleUnpack宏：专门用来解析元组
// RACTupleUnpack 等式右边：需要解析的元组
// 宏的参数，填解析的什么样数据 元组里面有几个值，宏的参数就必须填几个
RACTupleUnpack(id key,id value) = x;
NSLog(@"%@,%@,%@",key,value,[NSThread currentThread]);
} completed:^{
NSLog(@"字典解析完成");
}];
});
}];
打印内容如下：可以看出打印内容不再主线程
2018-01-04 16:39:31.657545+0800 MKJMWWM[2826:338427] 1,<NSThread: 0x604000279cc0>{number = 3, name = (null)}
2018-01-04 16:39:31.657865+0800 MKJMWWM[2826:338427] 2,<NSThread: 0x604000279cc0>{number = 3, name = (null)}
2018-01-04 16:39:31.658063+0800 MKJMWWM[2826:338427] 3,<NSThread: 0x604000279cc0>{number = 3, name = (null)}
2018-01-04 16:39:31.658219+0800 MKJMWWM[2826:338427] 4,<NSThread: 0x604000279cc0>{number = 3, name = (null)}
2018-01-04 16:39:31.658470+0800 MKJMWWM[2826:338427] 5,<NSThread: 0x604000279cc0>{number = 3, name = (null)}
2018-01-04 16:39:31.658636+0800 MKJMWWM[2826:338427] 6,<NSThread: 0x604000279cc0>{number = 3, name = (null)}
2018-01-04 16:39:31.658778+0800 MKJMWWM[2826:338427] 7,<NSThread: 0x604000279cc0>{number = 3, name = (null)}
2018-01-04 16:39:31.659790+0800 MKJMWWM[2826:338427] 遍历完成了,<NSThread: 0x604000279cc0>{number = 3, name = (null)}
2018-01-04 16:39:31.697010+0800 MKJMWWM[2826:338426] key3,333,<NSThread: 0x604000279240>{number = 4, name = (null)}
2018-01-04 16:39:31.697445+0800 MKJMWWM[2826:338426] key1,111,<NSThread: 0x604000279240>{number = 4, name = (null)}
2018-01-04 16:39:31.697844+0800 MKJMWWM[2826:338426] key4,(
M,
K,
J
),<NSThread: 0x604000279240>{number = 4, name = (null)}
2018-01-04 16:39:31.698190+0800 MKJMWWM[2826:338426] key2,222,<NSThread: 0x604000279240>{number = 4, name = (null)}
2018-01-04 16:39:31.698416+0800 MKJMWWM[2826:338426] 字典解析完成
RAC汇总表.png
