RACSubject 與 RACReplaySubject
RACReplaySubject *replaySubject = [RACReplaySubject subject];
[replaySubject sendNext:@"RACReplaySubject可以先發(fā)送消息再訂閱"];
[replaySubject subscribeNext:^(id x) {
NSLog(@"%@", x);
}];
RACSubject *subject = [RACSubject subject];
[subject subscribeNext:^(id x) {
NSLog(@"%@", x);
}];
[subject sendNext:@"subject只能先訂閱再發(fā)送消息"];