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在我们的应用程序中，我们需要在用户将应用程序推送到后台时取消注册。我们正在使用 PJSIP。我的应用程序DidEnterBackground：

- (void)applicationDidEnterBackground:(UIApplication *)application {
    NSLog(@"did enter background");


     __block UIBackgroundTaskIdentifier bgTask;

     bgTask = [application beginBackgroundTaskWithExpirationHandler:^{
        [application endBackgroundTask:bgTask];
        bgTask = UIBackgroundTaskInvalid;
    }];


    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        [self deregis];        
        [application endBackgroundTask: bgTask]; //End the task so the system knows that you are done with what you need to perform
        bgTask = UIBackgroundTaskInvalid; //Invalidate the background_task
        NSLog(@"\n\nRunning in the background!\n\n");

    });
     }

注销方法如下：

- (void)deregis {
    if (!pj_thread_is_registered())
    {
        pj_thread_register("ipjsua", a_thread_desc, &a_thread);
   }    
    dereg();

}

de-reg方法如下：

void dereg()
{
    int i;
    for (i=0; i<(int)pjsua_acc_get_count(); ++i) {
        if (!pjsua_acc_is_valid(i))
             pjsua_buddy_del(i);

        pjsua_acc_set_registration(i, PJ_FALSE);
    }
}

当我们将应用程序推送到后台时，会调用 dereg。但是当服务器发回 401 质询时，堆栈不会在 SIP 调用中发回身份验证详细信息，直到我将应用程序带回前台。有谁知道为什么会这样？

谢谢， 黑塔尔

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1 回答 1

1

您不想在后台线程中结束后台任务：

例如

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    [self deregis];        
    // don't do below...
    // [application endBackgroundTask: bgTask]; //End the task so the system knows that you are done with what you need to perform
    // bgTask = UIBackgroundTaskInvalid; //Invalidate the background_task
    NSLog(@"\n\nRunning in the background!\n\n");

});

您想在注册更新时结束后台任务。所以你需要挂钩 pjsua on_reg_state 回调。

例如，此示例可能只假设一个注销，对于多个帐户，您必须等到全部注销

-(void) regStateChanged: (bool)unregistered {
    if (unregistered && bgTask != UIBackgroundTaskInvalid) {
        [application endBackgroundTask: bgTask]; //End the task so the system knows that you are done with what you need to perform
        bgTask = UIBackgroundTaskInvalid; //Invalidate the background_task
    }
}
于 2011-09-26T00:27:33.180 回答