多线程iOS，快速启动UI

在我的ios应用程序中，我加入了谷歌、facebook和twitter的整合。当应用程序启动时，它在加载UI之前加载API

如何在我的UI加载时多线程，首先快速启动。我的Did FinishLaunchingwithOptions是

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    dispatch_async( dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        // Add code here to do background processing
        //
        //

        NSLog(@"Thread Excecution started");

        NSError* configureError;
        [[GGLContext sharedInstance] configureWithError: &configureError];
        NSAssert(!configureError, @"Error configuring Google services: %@", configureError);

        [GIDSignIn sharedInstance].delegate = self;


        [[FBSDKApplicationDelegate sharedInstance] application:application
                                 didFinishLaunchingWithOptions:launchOptions];

        dispatch_async( dispatch_get_main_queue(), ^{
            // Add code here to update the UI/send notifications based on the
            // results of the background processing

            NSLog(@"Thread Excecution completed");
        });
    });
    return YES;
}

---

如果您使用的是多线程，那么可以使用dispatch_group概念

dispatch_group_t group = dispatch_group_create();

//block 1
dispatch_group_async(group, dispatch_get_global_queue(0, 0), ^{
   // code here
});
//block 2
dispatch_group_async(group, dispatch_get_global_queue(0, 0), ^{
   // code here
});

//block 3
dispatch_group_notify(group, dispatch_get_global_queue(0, 0), ^{
   // block 3 will get notify, after block 1 and block 2 complete their tasks.
dispatch_async(dispatch_get_main_queue(), ^{

        [animationImageView stopAnimating];

        [self createUI];
    });
}

---

块1和块2将并行运行，完成工作后，块3将收到通知

你知道，即使在主线程上，也不能保证通知何时实际发出并被接收，对吗？您确定要这样做吗？为什么您需要在后台线程中编写外部API的启动代码？我可以在Viewdidload中添加这些代码吗？如果需要，您可以使用NSOperationQueue手动处理每个线程。再说一次，您在AppDidLaunch中执行此操作的具体问题是什么？不，如果框架说在AppDelegate中启动它，那么这就是你必须做的。现在还不清楚你到底有什么问题，你在寻求什么