無辜小表情
本片主要介紹RAC的方法和修飾符。
首先來說下什么是RAC,RAC給我們寫代碼帶來了什么便捷??赡軇傆龅降臅r候你會感覺這個東東太抽象了,入門好難,看著看著就沒興趣了。其實如果你進入它的世界,你會發(fā)現(xiàn)它的魅力,它會讓你的代碼寫起來更舒服,你會喜歡上它。
RAC基本構(gòu)造單元就是RACSignal,在它的眼里就是所有都是一個個信號在傳遞,你可以開始預先處理好運用邏輯并構(gòu)建你的信息流,而不用必須等到事件發(fā)生(命令式).也就是說你的處理事件、一些邏輯都是提前就已經(jīng)搞好了,只等待別人的訂閱就可以收到這個信號。
那么在什么時候使用呢?簡單點說就是原來需要委托, 回調(diào) block, 通知, KVO, target/action 事件觀察, 等,都可以用RAC信號來代替。信號會為了控制通過應用的信息流而獲得所有這些異步方法(委托, 回調(diào) block, 通知, KVO, target/action 事件觀察, 等)并將它們統(tǒng)一到一個接口下.這只是直觀理解. 不僅是這些, 因為信息會流過你的應用, 它還提供給你輕松轉(zhuǎn)換/分解/合并/過濾信息的能力.
首先來看下RAC的相關方法:
1. RAC發(fā)送消息,并且綁定到控件,最基本的使用。
-(void)racSenderMessage {
//延遲2.0S 發(fā)送消息
RACSignal *signal = [[RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
[subscriber sendNext:@"消息"];
[subscriber sendCompleted];
return [RACDisposable disposableWithBlock:^{
NSLog(@"一些處理事件");
}];
}] delay:2.0];
//將_userNameFeild的`text`屬性與映射后的信號量的值綁定到一起
RAC(_userNameFeild , text) = [signal map:^id(id value) {
if ([value isEqualToString:@"消息"]) {
return @"成功收到";
}
return nil;
}];
}
2. RAC代理,使用rac_signalForSelector這個方法來獲取代理信號.下邊是調(diào)用alertview的代理方法
-(void)racProtocolMothel {
RACSignal *protocolSignal = [self rac_signalForSelector:@selector(alertView:clickedButtonAtIndex:) fromProtocol:@protocol(UIAlertViewDelegate)];
[protocolSignal subscribeNext:^(id x) {
}];
}
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
}
3. RAC通知
-(void)racNotification {
//接受通知并且處理
[[[NSNotificationCenter defaultCenter] rac_addObserverForName:@"RAC_Notifaciotn" object:nil] subscribeNext:^(id x) {
// NSLog(@"notify.content = %@",notify.userInfo[@"content"]);
}];
//發(fā)出通知
[[NSNotificationCenter defaultCenter] postNotificationName:@"RAC_Notifaciotn" object:nil userInfo:@{@"content" : @"i'm a notification"}];
}
//* 4 RAC信號拼接 concat是signal1 completed之后 signal2才能執(zhí)行
-(void)racSignalLink {
RACSignal *signal1 = [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
[subscriber sendNext:@(1)];
[subscriber sendCompleted];
return nil;
}];
RACSignal *signal2 = [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
[subscriber sendNext:@(2)];
[subscriber sendCompleted];
return nil;
}];
RACSignal* concatSignal = [RACSignal concat:@[signal1,signal2]];
[concatSignal subscribeNext:^(id value) {
NSLog(@"RAC信號拼接------value = %@",value);
}];
//或者
// [[signal1 concat:signal2] subscribeNext:^(id value) {
// NSLog(@"RAC信號拼接------value = %@",value);
// }];
}
//* 5 RAC信號合并
-(void)racSignalMerge {
RACSignal *signal1 = [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
[subscriber sendNext:@"AA"];
[subscriber sendCompleted];
return nil;
}];
RACSignal *signal2 = [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
[subscriber sendNext:@"BB"];
[subscriber sendCompleted];
return nil;
}];
//合并操作
RACSignal* mergeSignal = [RACSignal merge:@[signal1,signal2]];
[mergeSignal subscribeNext:^(id x) {
NSLog(@"RAC信號合并------我喜歡: %@",x);
}];
//或者
// [[signal1 merge:signal2] subscribeNext:^(id x) {
// NSLog(@"RAC信號合并------我喜歡: %@",x);
// }];
}
//* 6 RAC信號組合(取信號量的最后發(fā)送的對象)
-(void)racSignalCombine {
RACSignal *signal1 = [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
[subscriber sendNext:@"SS"];
[subscriber sendNext:@"AA"];
[subscriber sendCompleted];
return nil;
}];
RACSignal *signal2 = [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
[subscriber sendNext:@"BB"];
[subscriber sendCompleted];
return nil;
}];
//combineLatest 將數(shù)組中的信號量發(fā)出的最后一個object 組合到一起
[[RACSignal combineLatest:@[signal1,signal2]] subscribeNext:^(id x) {
RACTupleUnpack(NSString *signal1_Str, NSString *signal2_Str) = (RACTuple *)x;
NSLog(@"RAC信號組合------我就是 %@ %@",signal1_Str,signal2_Str);
}];
//會注意收到 組合方法后還可以跟一個Block /** + (RACSignal *)combineLatest:(id<NSFastEnumeration>)signals reduce:(id (^)())reduceBlock */
/*
reduce這個Block可以對組合后的信號量做處理
*/
//我們還可以這樣使用
RACSignal * combineSignal =[RACSignal combineLatest:@[signal1,signal2] reduce:^(NSString *signal1_Str, NSString *signal2_Str){
return [signal1_Str stringByAppendingString:signal2_Str];
}];
[combineSignal subscribeNext:^(id x) {
NSLog(@"RAC信號組合(Reduce處理)------我喜歡 %@ 的",x);
}];
}
//* 7 RAC信號組合(取信號量的最開始發(fā)送的對象)全部獲取才會返回
/*當且僅當signalA和signalB同時都產(chǎn)生了值的時候,一個value才被輸出,signalA和signalB只有其中一個有值時會掛起等待另一個的值,所以輸出都是一對值(RACTuple)),當signalA和signalB只要一個先completed,RACStream也解散。*/
-(void)racSignalZIP {
RACSignal *signal1 = [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
[subscriber sendNext:@"AA"];
[subscriber sendNext:@"BB"];
[subscriber sendCompleted];
return nil;
}];
RACSignal *signal2 = [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
[subscriber sendNext:@"CC"];
[subscriber sendCompleted];
return nil;
}];
[[RACSignal zip:@[signal1,signal2]] subscribeNext:^(id x) {
RACTupleUnpack(NSString *signal1_Str, NSString *signal2_Str) = (RACTuple *)x;
NSLog(@"RAC信號壓縮------我是 %@的 %@的 ",signal1_Str, signal2_Str);
}];
}
//* 8 RAC信號過濾
-(void)racSignalFilter {
[[[RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
[subscriber sendNext:@(19)];
[subscriber sendNext:@(12)];
[subscriber sendNext:@(20)];
[subscriber sendCompleted];
return nil;
}] filter:^BOOL(id value) {
NSNumber *numberValue = value;
if(numberValue.integerValue < 18) {
//18禁
NSLog(@"RAC信號過濾------FBI Warning~");
}
return numberValue.integerValue > 18;
}] subscribeNext:^(id x) {
NSLog(@"RAC信號過濾------年齡:%@",x);
}];
}
// 9 RAC信號傳遞(傳遞數(shù)值,前后信號有聯(lián)系)
-(void)racSignalPass {
[[[[RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
[subscriber sendNext:@"老板向我扔過來一個Star"];
return nil;
}] flattenMap:^RACStream *(id value) {
NSLog(@"RAC信號傳遞flattenMap1------%@",value);
RACSignal *tmpSignal = [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
[subscriber sendNext:[NSString stringWithFormat:@"%@----我向老板扔回一塊板磚",value]];
return nil;
}];
return tmpSignal;
}] flattenMap:^RACStream *(id value) {
NSLog(@"RAC信號傳遞flattenMap2------%@",value);
return [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
[subscriber sendNext:[NSString stringWithFormat:@"%@---我跟老板正面剛~,結(jié)果可想而知",value]];
return nil;
}];
}] subscribeNext:^(id x) {
NSLog(@"RAC信號傳遞last------%@",x);
}];
}
//* 10 RAC信號傳遞(不傳遞數(shù)值)
-(void)racSignalQueue {
//與信號傳遞類似,不過使用 `then` 表明的是秩序,沒有傳遞value
[[[[RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
NSLog(@"RAC信號串------我先來");
[subscriber sendCompleted];
return nil;
}] then:^RACSignal *{
return [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
NSLog(@"RAC信號串------我第二");
[subscriber sendCompleted];
return nil;
}];
}] then:^RACSignal *{
return [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
NSLog(@"RAC信號串------我第三");
[subscriber sendCompleted];
return nil;
}];
}] subscribeNext:^(id x) {
NSLog(@"RAC信號串------Over");
}];
}
//* 11 RAC_Command介紹
-(void)racCommandDemo {
RACCommand *command = [[RACCommand alloc] initWithSignalBlock:^RACSignal *(id input) {
return [RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
NSLog(@"racCommandDemo------");
[subscriber sendCompleted];
return nil;
}];
}];
//命令執(zhí)行
[command execute:nil];
}
上邊是部分RAC方法的理解。