GetFileAsync挂起 [英] GetFileAsync hangs

问题描述

我使用下面的代码，但不知何故，代码停在：  StorageFile fileToRead = await storageFolder.GetFileAsync（" cameras.xml"）;

在某些论坛上，据说您必须将其调整为：  StorageFile fileToRead = await storageFolder.GetFileAsync （"cameras.xml"）。ConfigureAwait（False）;

但是有一个错误消息：  IAsyncOperation不包含ConfigureAwait的定义

有人知道解决方案吗？

这是我用过的任务代码：

 public static async System.Threading.Tasks.Task< List< Camera>> LoadCameraXmlAsync（）
 
 {
 //从xml文件加载相机列表
 XDocument xmlDoc = new XDocument（）; 
列表<相机> cameraList = new List< Camera>（）; 
 Windows.Storage.StorageFolder storageFolder = 
 Windows.Storage.ApplicationData.Current.LocalFolder; 
 bool fileExists = File.Exists（storageFolder.Path +" \\cameras.xml"）; 
 if（fileExists）
 {
 StorageFile fileToRead = await storageFolder.GetFileAsync（" cameras.xml"）。ConfigureAwait（false）; 
 using（var stream = await fileToRead.OpenStreamForReadAsync（））
 {
 xmlDoc = XDocument.Load（stream）; 
 stream.Flush（）; 
} 
 
使用（var reader = xmlDoc.CreateReader（））
 {
 //从作者读取xml 
 var serializer = new XmlSerializer（的typeof（摄像机））; 
 cameraList =（List< Camera>）serializer.Deserialize（reader）; 
} 
} 
返回cameraList; 
} 

解决方案

您好，

您是如何从代码中调用LoadCameraXmlAsync的？您是否尝试过以下代码：

 StorageFile fileToRead = await storageFolder.GetFileAsync（" cameras.xml"）。AsTask（）。ConfigureAwait（false）; 
 

以下是有关为何使用ConfigureAwait的详细信息。

https://stackoverflow.com/questions/11316438/call-to-await-getfileasync-never-returns-and-app-hangs-in-winrt-app

此处的最佳做法是：

有两种避免这种情况的最佳做法：

1. In您的异步方法，尽可能使用ConfigureAwait（false）。
2. 不要阻止任务;一直使用async。

祝你好运，

Barry

I use the code below, but somehow the code stops at: StorageFile fileToRead = await storageFolder.GetFileAsync("cameras.xml");

On some forums it is said that you have to adjust it to: StorageFile fileToRead = await storageFolder.GetFileAsync("cameras.xml").ConfigureAwait(False);

But then there is an errormessage: IAsyncOperation does not contain a definition for ConfigureAwait

Does somebody knows a solution?

This is my used code for the task:

public static async System.Threading.Tasks.Task<List<Camera>> LoadCameraXmlAsync()

        {
            //load list of camera's from xml file
            XDocument xmlDoc = new XDocument();
            List<Camera> cameraList = new List<Camera>();
            Windows.Storage.StorageFolder storageFolder =
                Windows.Storage.ApplicationData.Current.LocalFolder;
            bool fileExists = File.Exists(storageFolder.Path + "\\cameras.xml");
            if (fileExists)
                {
                    StorageFile fileToRead = await storageFolder.GetFileAsync("cameras.xml").ConfigureAwait(false);
                    using (var stream = await fileToRead.OpenStreamForReadAsync())
                    {
                        xmlDoc = XDocument.Load(stream);
                        stream.Flush();
                    }

                    using (var reader = xmlDoc.CreateReader())
                    {
                        // read xml from the writer
                        var serializer = new XmlSerializer(typeof(Camera));
                        cameraList = (List<Camera>) serializer.Deserialize(reader);
                    }
                }
            return cameraList;
        }

解决方案

Hello,

How did you call LoadCameraXmlAsync from your code? Have you tried the following code:

 StorageFile fileToRead = await storageFolder.GetFileAsync("cameras.xml").AsTask().ConfigureAwait(false);

Here is the detail about why ConfigureAwait is used here.

https://stackoverflow.com/questions/11316438/call-to-await-getfileasync-never-returns-and-app-hangs-in-winrt-app

And best practices here is:

There are two best practices that avoid this situation:

1. In your async methods, use ConfigureAwait(false) wherever possible.
2. Don’t block on Tasks; use async all the way down.

Best regards,

Barry

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