ReactiveCocoa 在实际项目中的使用（二）联合操作

[ReactiveCocoa 在实际项目中的使用（一）基本操作](http://www.jianshu.com/p/06db839745ec) #1、merge 操作 merge 是合并的意思，将两个或者多个信号合并，两个信号发送的 next 会汇聚到一起发送到合并后的信号的 next 事件中。两个信号都发送了完成事件后合并后的信号才会发送完成事件。 ``` NSArray *numArray = @[@1, @2, @3, @4, @5];// 创建一个数字数组 RACSignal *numSignal = [numArray.rac_sequence signalWithScheduler:RACScheduler.mainThreadScheduler]; //数字数组转换成信号 NSArray *stringArrray = @[@"a", @"b", @"c", @"d", @"e", @"f"]; // 创建字符串数组 RACSignal *stringSignal = [stringArrray.rac_sequence signalWithScheduler:RACScheduler.mainThreadScheduler]; // 字符串数组转成信号 [[numSignal merge:stringSignal] subscribeNext:^(id _Nullable x) { //合并两个信号 NSLog(@"%@",x); } completed:^{ NSLog(@"%@",@"done"); }]; Result: 2017-08-21 16:23:18.170228+0800 ReactiveCocoaDemo[356:50482] 1 2017-08-21 16:23:18.170587+0800 ReactiveCocoaDemo[356:50482] a 2017-08-21 16:23:18.170805+0800 ReactiveCocoaDemo[356:50482] 2 2017-08-21 16:23:18.171007+0800 ReactiveCocoaDemo[356:50482] b 2017-08-21 16:23:18.171214+0800 ReactiveCocoaDemo[356:50482] 3 2017-08-21 16:23:18.171413+0800 ReactiveCocoaDemo[356:50482] c 2017-08-21 16:23:18.171614+0800 ReactiveCocoaDemo[356:50482] 4 2017-08-21 16:23:18.171812+0800 ReactiveCocoaDemo[356:50482] d 2017-08-21 16:23:18.172032+0800 ReactiveCocoaDemo[356:50482] 5 2017-08-21 16:23:18.172377+0800 ReactiveCocoaDemo[356:50482] e 2017-08-21 16:23:18.172738+0800 ReactiveCocoaDemo[356:50482] f 2017-08-21 16:23:18.173014+0800 ReactiveCocoaDemo[356:50482] done ``` #2、zipWith 操作 对几个信号发送的 next 事件进行压缩合并 ``` NSArray *numArray = @[@1, @2, @3, @4, @5];// 创建一个数字数组 RACSignal *numSignal = [numArray.rac_sequence signalWithScheduler:RACScheduler.mainThreadScheduler]; //数字数组转换成信号 NSArray *stringArrray = @[@"a", @"b", @"c", @"d", @"e", @"f"]; // 创建字符串数组 RACSignal *stringSignal = [stringArrray.rac_sequence signalWithScheduler:RACScheduler.mainThreadScheduler]; // 字符串数组转成信号 [[[numSignal zipWith:stringSignal] //压缩两个信号 reduceEach:^(NSNumber *num, NSString *string){ // 对返回的数据进行解压 return [NSString stringWithFormat:@"%@%@", num, string]; }] subscribeNext:^(id _Nullable x) { //合并两个信号 NSLog(@"%@",x); } completed:^{ NSLog(@"%@",@"done"); }]; Result: 2017-08-21 16:27:21.261630+0800 ReactiveCocoaDemo[362:51836] 1a 2017-08-21 16:27:21.262515+0800 ReactiveCocoaDemo[362:51836] 2b 2017-08-21 16:27:21.263100+0800 ReactiveCocoaDemo[362:51836] 3c 2017-08-21 16:27:21.263647+0800 ReactiveCocoaDemo[362:51836] 4d 2017-08-21 16:27:21.264318+0800 ReactiveCocoaDemo[362:51836] 5e 2017-08-21 16:27:21.264689+0800 ReactiveCocoaDemo[362:51836] done ``` #3、combineLatest 操作 取联合的多个信号中的最新出现的值发送出来 ``` NSArray *numArray = @[@1, @2, @3, @4, @5];// 创建一个数字数组 RACSignal *numSignal = [numArray.rac_sequence signalWithScheduler:RACScheduler.mainThreadScheduler]; //数字数组转换成信号 NSArray *stringArrray = @[@"a", @"b", @"c", @"d"]; // 创建字符串数组 RACSignal *stringSignal = [stringArrray.rac_sequence signalWithScheduler:RACScheduler.mainThreadScheduler]; // 字符串数组转成信号 [[[RACSignal combineLatest:@[numSignal, stringSignal]] reduceEach:^(NSNumber *num, NSString *str){ // 联合两个信号中最新的值传入 reduceEach处理 return [NSString stringWithFormat:@"%@%@",num, str]; //拼接两个value }] subscribeNext:^(NSString *x) { NSLog(@"%@",x); } completed:^{ NSLog(@"done"); }]; Result: 2017-08-21 16:16:06.597646+0800 ReactiveCocoaDemo[348:48433] 1a 2017-08-21 16:16:06.598708+0800 ReactiveCocoaDemo[348:48433] 2a 2017-08-21 16:16:06.599337+0800 ReactiveCocoaDemo[348:48433] 2b 2017-08-21 16:16:06.599928+0800 ReactiveCocoaDemo[348:48433] 3b 2017-08-21 16:16:06.600483+0800 ReactiveCocoaDemo[348:48433] 3c 2017-08-21 16:16:06.601214+0800 ReactiveCocoaDemo[348:48433] 4c 2017-08-21 16:16:06.601999+0800 ReactiveCocoaDemo[348:48433] 4d 2017-08-21 16:16:06.602748+0800 ReactiveCocoaDemo[348:48433] 5d 2017-08-21 16:16:06.603451+0800 ReactiveCocoaDemo[348:48433] done ``` #4、concat 操作 concat 是连接两个信号的操作符。它必须等待前一个信号发送了 completed 信号后才会发送后一个信号的next 事件和 completed 事件 ``` NSArray *numArray = @[@1, @2, @3, @4, @5];// 创建一个数字数组 RACSignal *numSignal = [numArray.rac_sequence signalWithScheduler:RACScheduler.mainThreadScheduler]; //数字数组转换成信号 NSArray *stringArrray = @[@"a", @"b", @"c", @"d", @"e", @"f"]; // 创建字符串数组 RACSignal *stringSignal = [stringArrray.rac_sequence signalWithScheduler:RACScheduler.mainThreadScheduler]; // 字符串数组转成信号 [[numSignal concat:stringSignal] // 连接两个信号 subscribeNext:^(id _Nullable x) { NSLog(@"%@",x); } completed:^{ NSLog(@"%@",@"done"); }]; Resilt: 2017-08-21 17:23:18.741757+0800 ReactiveCocoaDemo[418:66579] 1 2017-08-21 17:23:18.742078+0800 ReactiveCocoaDemo[418:66579] 2 2017-08-21 17:23:18.742264+0800 ReactiveCocoaDemo[418:66579] 3 2017-08-21 17:23:18.742441+0800 ReactiveCocoaDemo[418:66579] 4 2017-08-21 17:23:18.742616+0800 ReactiveCocoaDemo[418:66579] 5 2017-08-21 17:23:18.743216+0800 ReactiveCocoaDemo[418:66579] a 2017-08-21 17:23:18.743409+0800 ReactiveCocoaDemo[418:66579] b 2017-08-21 17:23:18.743582+0800 ReactiveCocoaDemo[418:66579] c 2017-08-21 17:23:18.743753+0800 ReactiveCocoaDemo[418:66579] d 2017-08-21 17:23:18.743924+0800 ReactiveCocoaDemo[418:66579] e 2017-08-21 17:23:18.744094+0800 ReactiveCocoaDemo[418:66579] f 2017-08-21 17:23:18.744311+0800 ReactiveCocoaDemo[418:66579] done ```