Ios 等待另一个委托的目标c块

我有一个watchkit应用程序，可以调用iphone应用程序上的viewcontroller。我有一个网络连接的代理。我试图使用一个块，这样我就不会将AppDelegate和视图控制器紧密地结合在一起。当代理完成时，我如何通知我的区块

ViewController.m

-(void)getWatchDataWithCompletion:(void(^)(BOOL gotData))completion{
   [self setUpAppForWatch];
   completion(YES);
}

-(void)finishedMessageParse:(NSMutableData *)messageData{
   //the delegate is finish tell the block completion is done.

}

-(void)setUpAppForWatch{
   [network call];
}

AppDelegate.m

-(void)application:(UIApplication *)application handleWatchKitExtensionRequest:(NSDictionary *)userInfo reply:(void (^)
(NSDictionary *))reply{

[vc getWatchDataWithCompletion:^(BOOL gotData){
    if (gotData){
       //I'm done reply dictionary
       reply(@{@"data":serlizedData})
}];

---

有三种可能的方法

)；tldr-参考第三个。否则-阅读所有内容，可能会有用

第一个

使用专用串行队列执行

finished…

方法和块的任务。如果

已完成…

始终在块之前调用，您就足够了。如果没有，请查看第二个

使用private

@property dispatch\u queue\u t privateSerialQueue

privateSerialQueue = dispatch_queue_create("PrivateQueue", DISPATCH_QUEUE_SERIAL);

然后，像这样使用它

-(void)getWatchDataWithCompletion:(void(^)(BOOL gotData))completion{
    [self setUpAppForWatch];
    dispatch_async(privateSerialQueue, ^(){
       completion(YES);
    });
}

-(void)finishedMessageParse:(NSMutableData *)messageData{
    dispatch_sync(privateSerialQueue, ^(void){
            //Here goes whatever you need to do in this method before block start
    });
    //the delegate is finish tell the block completion is done.
}

-(void)getWatchDataWithCompletion:(void(^)(BOOL gotData))completion{
    [self setUpAppForWatch];
    dispatch_semaphore_wait(self.semaphore, DISPATCH_TIME_FOREVER);
    completion(YES);
}

-(void)finishedMessageParse:(NSMutableData *)messageData{
  //the delegate is finish tell the block completion is done.
  dispatch_semaphore_signal(self.semaphore);
}

第二个

看看调度信号灯。使其成为视图控件的公共属性

@property（只读）调度信号量

使用起始值0创建它。如果块在委托
完成…
方法之前运行，它将允许您等待，如果
完成
在块之前已经完成，则立即运行。像这样

self.semaphore = dispatch_semaphore_create(0); 

那么你可以这样使用它

-(void)finishedMessageParse:(NSMutableData *)messageData{
  //the delegate is finish tell the block completion is done.
  dispatch_semaphore_signal(self.semaphore);
}

[vc getWatchDataWithCompletion:^(BOOL gotData){
    if (gotData){
       //I'm done reply dictionary
       dispatch_semaphore_wait(vc.semaphore, DISPATCH_TIME_FOREVER);
       reply(@{@"data":serlizedData})
}];

第三个

我在写上面两个时想到了=）
前两者的某种组合

使用视图控制器的私有属性
@property（只读）调度信号量

以与第二个相同的方式初始化它（起始值为0）

像这样私下使用它

-(void)getWatchDataWithCompletion:(void(^)(BOOL gotData))completion{
    [self setUpAppForWatch];
    dispatch_async(privateSerialQueue, ^(){
       completion(YES);
    });
}

-(void)finishedMessageParse:(NSMutableData *)messageData{
    dispatch_sync(privateSerialQueue, ^(void){
            //Here goes whatever you need to do in this method before block start
    });
    //the delegate is finish tell the block completion is done.
}

-(void)getWatchDataWithCompletion:(void(^)(BOOL gotData))completion{
    [self setUpAppForWatch];
    dispatch_semaphore_wait(self.semaphore, DISPATCH_TIME_FOREVER);
    completion(YES);
}

-(void)finishedMessageParse:(NSMutableData *)messageData{
  //the delegate is finish tell the block completion is done.
  dispatch_semaphore_signal(self.semaphore);
}

另外，希望，它能帮助你抓住重点。请随意询问任何不清楚的问题
在viewcontroller中添加新属性：

@property (nonatomic, strong) void(^completion)(BOOL gotData);


-(void)getWatchDataWithCompletion:(void(^)(BOOL gotData))completion{
   [self setUpAppForWatch];
   self.completion = completion;
}

-(void)finishedMessageParse:(NSMutableData *)messageData{
    if (self.completion){
        self.completion(YES);
    }
}

在这种情况下，您的完成块可能不会被称为“永不”。完美，正是我所缺少的。