Question

我对Windows手机开发相对较新，而且我坚持这一点。我正在尝试运行后台资源密集型代理，该代理会在应用程序停用时发出网络请求。以下是代码的所有重要部分..

 private void Application_Deactivated(object sender, DeactivatedEventArgs e)
    {
        StartResourceIntensiveAgent();
        Debug.WriteLine("App deactivating.");

    }

private void StartResourceIntensiveAgent()
    {
        // Variable for tracking enabled status of background agents for this app.
        Debug.WriteLine("Starting NetworkRequestTaskAgent.");
        string resourceIntensiveTaskName = "NetworkRequestTaskAgent";
        ResourceIntensiveTask resourceIntensiveTask = ScheduledActionService.Find(resourceIntensiveTaskName) as ResourceIntensiveTask;
        // If the task already exists and background agents are enabled for the
        // application, you must remove the task and then add it again to update 
        // the schedule.
        if (resourceIntensiveTask != null)
        {
            RemoveAgent(resourceIntensiveTaskName);
        }

        resourceIntensiveTask = new ResourceIntensiveTask(resourceIntensiveTaskName);

        // The description is required for periodic agents. This is the string that the user
        // will see in the background services Settings page on the device.
        resourceIntensiveTask.Description = "This demonstrates a resource-intensive task.";

        // Place the call to Add in a try block in case the user has disabled agents.
        try
        {
            ScheduledActionService.Add(resourceIntensiveTask);
            // If debugging is enabled, use LaunchForTest to launch the agent in one minute.
        }
        catch (InvalidOperationException exception)
        {
            if (exception.Message.Contains("BNS Error: The action is disabled"))
            {
                MessageBox.Show("Background agents for this application have been disabled by the user.");
            }
        }
        catch (SchedulerServiceException)
        {

        }
    }

和ScheduledAgent.cs

protected override void OnInvoke(ScheduledTask task)
    {
        //TODO: Add code to perform your task in background
        if (task is ResourceIntensiveTask)
        {
            string ToastMessage = "ResourceIntensiveTask is running";
            ShellToast Toast = new ShellToast();
            Toast.Title = "Background agent sample";
            Toast.Content = ToastMessage;
            Toast.Show();
            string url = "http://someserver.net:8080/MultipleDeviceServ/javaQuery?request=sendId&title=deactivatedtest&id=deactivatedtest";
            HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
            request.BeginGetResponse(httpComplete, request);
        }
        NotifyComplete();
    }

    private static void httpComplete(IAsyncResult asyncResult)
    {
        Debug.WriteLine("Trying web request..");
        HttpWebRequest request = asyncResult.AsyncState as HttpWebRequest;
        if (request != null)
        {
            try
            {
                Debug.WriteLine("Web request has gone through.");
            }
            catch (WebException e)
            {
                return;
            }
        }
    }

现在我不确定后台任务是否开始运行，但是函数StartResourceIntensiveAgent（）会在调试行打印＆＃34;启动NetworkRequestTaskAgent时运行。除此之外，我对可能出现的错误知之甚少，我唯一的假设是，即使我将任务代理命名为NetworkRequestTaskAgent，它也可能与StartResourceIntensiveAgent函数中的部分无关＆＃34; string resourceIntensiveTaskName =＆＃34 ; NetworkRequestTaskAgent＆＃34 ;;任何形式的见解都会非常有用。

Answer 1

我没有注意到快速查看中的错误。

您已创建

的实例

resourceIntensiveTask = new ResourceIntensiveTask (resourceIntensiveTaskName);

在'ScheduledActionService'中激活后台代理。添加（'resourceIntensiveTask'）;

在'OnInvoke'上放置一个断点并等待后台代理的启动。调试器允许您逐步完成。

您可以在设备模拟器或设置/ Batarey保护程序中看到后台代理在wp 8.1中工作。

WP8后台代理网络请求

1 个答案: