ios - 信号宽限期

Question

当对象的属性 isWorking 设置为 YES 时，屏幕上应显示一个事件指示器。此代码修复了:

[RACObserve(object, isWorking) subscribeNext:^(NSNumber *isWorking) {
  if ([isWorking boolValue]) {
    [activityIndicator startAnimating];
  }
  else {
    [activityIndicator stopAnimating];
  }
}];

除非经过一定时间(比如 1 秒)，否则如何防止信号触发。这将防止事件指示器闪烁。

节流不会在这种情况下进行，对吧？

Answer 1

当 isWorking 等于 YES 时，我会包装原始信号以引入延迟。像下面这样的东西。

RACSignal *isWorkingSignal = [[RACObserve(object, isWorking)
        map:^id(NSNumber *isWorking) {
            if (YES == [isWorking boolValue]) {
                NSTimeInterval delayInterval = 2; // seconds
                return [[RACSignal return:isWorking] delay:delayInterval];
            } else {
                return [RACSignal return:isWorking];
            }
        }] switchToLatest];

[isWorkingSignal subscribeNext:^(NSNumber *isWorking) {
    if (YES == [isWorking boolValue]) {
        [activityIndicator startAnimating];
    }
    else {
        [activityIndicator stopAnimating];
    }
}];