iphone - 苹果多任务处理代码中的错误

事实上，我正在为多任务和面对错误，请帮助我，因为我需要工作的背景应用，也在前景应用

 - (void)applicationDidEnterBackground:(UIApplication *)application
{
    UIApplication*    app = [UIApplication sharedApplication];

    // Request permission to run in the background. Provide an
    // expiration handler in case the task runs long.
    NSAssert(bgTask == UIBackgroundTaskInvalid, nil);

    bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
        // Synchronize the cleanup call on the main thread in case
        // the task actually finishes at around the same time.
        dispatch_async(dispatch_get_main_queue(), ^{
            if (bgTask != UIBackgroundTaskInvalid)
            {
                [app endBackgroundTask:bgTask];
                bgTask = UIBackgroundTaskInvalid;
            }
        });
    }];

    // Start the long-running task and return immediately.
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

        // Do the work associated with the task.

        // Synchronize the cleanup call on the main thread in case
        // the expiration handler is fired at the same time.
        dispatch_async(dispatch_get_main_queue(), ^{
            if (bgTask != UIBackgroundTaskInvalid)
            {
                [app endBackgroundTask:bgTask];
                bgTask = UIBackgroundTaskInvalid;
            }
        });
    });
}

最佳答案

输入@interface：

UIBackgroundTaskIdentifier bgTask;

（从保密协议中删除）。

关于iphone - 苹果多任务处理代码中的错误，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/3057928/