Windows Phone C＃ - system.unauthorizedaccessexception

Question

Hellllooooo家伙！

我有一个适用于Windows Phone 8的应用程序。我的应用程序的崩溃报告列出了一个经常发生的非常大的错误（崩溃计数很高）。有趣的（让我们说悲伤）是我无法在手机或模拟器上重现此错误。你能帮帮我吗？

错误是：

problem function: MyAppName.More+_writeToFile_d__11.MoveNext
exception type: system.unauthorizedaccessexception
stacktrace: "Frame  Bild   Funktion       Offset        
0        mscorlib_ni    
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess                        
0x0023a00e    
1        mscorlib_ni    
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification   
0x0000003a    
2        mscorlib_ni     System.Runtime.CompilerServices.TaskAwaiter_
[[System.__Canon,_mscorlib]].GetResult    0x0000001c    
3        myAppName_ni   
MyAppName.More+_writeToFile_d__11.MoveNext                                            
0x000001cc    
4        mscorlib_ni   
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess                        
0x0023a00e    
5        mscorlib_ni    
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification   
0x0000003a    
6        mscorlib_ni   
System.Runtime.CompilerServices.TaskAwaiter.GetResult                                
0x0000001a    
7        myAppName_ni  
MyAppName.More+_readFile_d__1b.MoveNext                                               
0x000002f8    
8        mscorlib_ni    
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess                        
0x0023a00e    
9        mscorlib_ni    
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification   
0x0000003a    
10       mscorlib_ni    
System.Runtime.CompilerServices.TaskAwaiter.GetResult                                 
0x0000001a    
11       myAppName_ni   
MyAppName.MainPage+_buttonLike_Click_d__60.MoveNext                                   
0x0000073e    
12       mscorlib_ni    
System.Runtime.CompilerServices.AsyncMethodBuilderCore._ThrowAsync_b__0                0x00000036"

我正在使用方法“writeToFile”：

await readFile();
await writeToFile((pointsCount + 200).ToString());
await readFile();

方法“writeToFile”就是这个：

    public static async Task writeToFile(string text)
    {
        // Get the text data from the parameter. 
        byte[] fileBytes = System.Text.Encoding.UTF8.GetBytes(text.ToCharArray());

        // Get the local folder.
        StorageFolder local = Windows.Storage.ApplicationData.Current.LocalFolder;

        // Create a new folder name DataFolder.
        var dataFolder = await local.CreateFolderAsync("DataFolder",
            CreationCollisionOption.OpenIfExists);

        // Create a new file named DataFile.txt.
        var file = await dataFolder.CreateFileAsync("DataFile.txt",
        CreationCollisionOption.ReplaceExisting);

        // Write the data from the parameter.
        using (var s = await file.OpenStreamForWriteAsync())
        {
            s.Write(fileBytes, 0, fileBytes.Length);
        }
    }

方法“readFile”是这样的：

    public static async Task readFile()
    {
        // Get the local folder.
        StorageFolder local = Windows.Storage.ApplicationData.Current.LocalFolder;

        if (local != null)
        {
            if (Directory.Exists(local.Path + @"\DataFolder"))
            {
                // Get the DataFolder folder.
                var dataFolder = await local.GetFolderAsync("DataFolder");

                if (File.Exists(dataFolder.Path + @"\DataFile.txt"))
                {
                    // Get the file.
                    var file = await dataFolder.OpenStreamForReadAsync("DataFile.txt");
                    if (file.Length > 0)
                    {
                        // Read the data.
                        using (StreamReader streamReader = new StreamReader(file))
                        {
                            pointsCount = Convert.ToInt32(streamReader.ReadToEnd());
                        }
                    }
                    else
                    {
                        await writeToFile("0");
                        await readFile();
                    }
                }
                else
                {
                    await writeToFile("0");
                    await readFile();
                }
            }
            else
            {
                await writeToFile("0");
                await readFile();
            }

        }
    }