什么是RAC
ReactiveCocoa框架具有响应式编程的特点，能精简代码，优化逻辑，去除了协议代理等的引用
RAC能干什么
使用事件流统一了OC的事件处理和异步处理
-委托
-通知
-UIKit事件
-KVO
-回调block
RAC使用示例
1.代替委托
- (RACSignal *)rac_signalForSelector:(SEL)selector fromProtocol:(Protocol *)protocol{}
2.代替通知
[[[NSNotificationCenter defaultCenter] rac_addObserverForName:UIKeyboardWillShowNotification object:nil] subscribeNext:^(id x) {
NSLog(@"%@",x);
}];
3.代替UIKit事件
[[button rac_signalForControlEvents:UIControlEventTouchUpInside] subscribeNext:^(id x) {
}];
[[(UITextView *)text rac_textSignal] subscribeNext:^(id x) {
}];
4.代替KVO
[[button rac_valuesForKeyPath:@"frame" observer:nil] subscribeNext:^(id x) {
}];
//此方法订阅next事件
- (RACDisposable *)subscribeNext:(void (^)(id x))nextBlock{}
//如果不想订阅
[(RACDisposable*)disposable dispose];
//多个信号都接收到了才执行selector
- (RACSignal *)rac_liftSelector:(SEL)selector withSignalsFromArray:(NSArray *)signals{}
//多播信号 我的理解就是有多处订阅信号，创建信号的block只执行一次
- (void)test {
__block NSUInteger b = a;
RACSignal *sourceSignal = [RACSignal createSignal:^RACDisposable * _Nullable(id<RACSubscriber> _Nonnull subscriber) {
b++;
NSLog(@"调用了数据:%@", [NSDate date]);
[subscriber sendNext:nil];
return nil;
}];
RACMulticastConnection *connection = [sourceSignal publish];
[connection.signal subscribeNext:^(id _Nullable x) {
NSString *dataString = [[NSString alloc] initWithData:x encoding:NSUTF8StringEncoding];
NSLog(@"A处调用了数据:%@ b = %ld", dataString,b);
}];
[connection.signal subscribeNext:^(id _Nullable x) {
NSString *dataString = [[NSString alloc] initWithData:x encoding:NSUTF8StringEncoding];
NSLog(@"B处调用了数据:%@ b = %ld", dataString,b);
}];
[connection connect];
}
输出
2017-06-22 16:43:02.641 ReactiveCocoaTest[16910:634484] 调用了数据:2017-06-22 08:43:02 +0000
2017-06-22 16:43:02.641 ReactiveCocoaTest[16910:634484] A处调用了数据: b = 1
2017-06-22 16:43:02.642 ReactiveCocoaTest[16910:634484] B处调用了数据: b = 1
//RACCommand
[button setRac_command:[[RACCommand alloc] initWithEnabled:nil signalBlock:^RACSignal *(id input) {
return [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
NSLog(@"Clicked");
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(3.0*NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
[subscriber sendNext:[[NSDate date] description]];
[subscriber sendCompleted];
});
return [RACDisposable disposableWithBlock:^{
}];
}];
}]];
//bind
UIAlertView alertView = [[UIAlertView alloc] initWithTitle:@"RAC" message:@"RAC TEST" delegate:self cancelButtonTitle:@"cancel" otherButtonTitles:@"other", nil];
[[alertView.rac_buttonClickedSignal bind:^RACStreamBindBlock{
return ^RACStream(id value,BOOL *stop){
return [RACReturnSignal return:[NSString stringWithFormat:@"%@",value]];
};
}] subscribeNext:^(id x) {
NSLog(@"%@",x);
}];
