CreateQueryWithOptions 导致系统互操作 Com 异常

Question

好的，所以我有一个简单的 uwp 应用程序，我正在尝试从 KnownFolders.VideoLibrary 获取数据并使其更快，我正在使用 indexing 与 QueryOptions。奇怪的是，在第一次加载页面时我没有收到任何错误，但是当我尝试深入另一个文件夹并再次导航到同一页面时，我得到了这个 Com Exception

Error is of type System.Runtime.InteropServices.COMException

Error HRESULT E_FAIL has been returned from a call to a COM component

我的 ViewModel 中的 FillFolders 方法**

private async Task FillUpFolders()
    {
        uint index = 0, stepSize = 5;
        //on the first load of the LibraryPage I dont get any exception
        //but on the 2nd load, I get exception on the line below.
        var VideoQuery = FileHelper.GetVideoFoldersQuery(MainFolder, 200);
        IReadOnlyList<StorageFolder> folders = await VideoQuery.GetFoldersAsync(index, stepSize);
        index += 5;
        while (folders.Count != 0)
        {
            var folderTask = VideoQuery.GetFoldersAsync(index, stepSize).AsTask();
            foreach (StorageFolder folder in folders)
            {
                var vv = new Folder
                {
                    MyStorageFolder = folder,
                    Title = folder.DisplayName,
                    Thumbnail = new BitmapImage(new Uri("ms-appx:///Assets/FolderIcon.png")),
                    MyStretch = Windows.UI.Xaml.Media.Stretch.Uniform
                };
                Source.Add(vv);
            }
            folders = await folderTask;
            index += 5;
        }
    }

视频文件查询方法

internal static StorageFolderQueryResult GetVideoFoldersQuery(StorageFolder Folder, uint thumbnailRequestedSize)
    {
        if (videoFolderOptions is null)
        {
            videoFolderOptions = new QueryOptions(CommonFolderQuery.DefaultQuery)
            {
                IndexerOption = IndexerOption.OnlyUseIndexerAndOptimizeForIndexedProperties//check sort order later               
            };
            videoFolderOptions.SetThumbnailPrefetch(ThumbnailMode.VideosView, thumbnailRequestedSize, ThumbnailOptions.UseCurrentScale);
        }
        return Folder.CreateFolderQueryWithOptions(videoFolderOptions);
    }

I am providing my project on a github repo so anyone can easily reproduce the problem and easily can analyze it.

https://github.com/touseefbsb/UWPStorageFolderBug

StackTrace

" at Windows.Storage.StorageFolder.CreateFolderQueryWithOptions(QueryOptions queryOptions)\r\n at Fluent_Video_Player.Helpers.FileHelper.GetVideoFoldersQuery(StorageFolder Folder, UInt32 thumbnailRequestedSize)\r\n at Fluent_Video_Player.ViewModels.LibraryViewModel.d__11.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.GetResult()\r\n at Fluent_Video_Player.ViewModels.LibraryViewModel.d__9.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.GetResult()\r\n at Fluent_Video_Player.Views.LibraryPage.d__5.MoveNext()"

重现步骤

克隆存储库
在VS 2017中打开解决方案
运行应用
从左侧导航菜单转到图书馆页面（注意这里没有错误）
单击任何文件夹以深入了解它
现在你会得到这个异常。

Note : I tried to do ConfigureAwait(false) with Fill() method on LibraryPage.xaml.cs and FillUpFolders() and FillUpFiles() methods within the viewmodel this lead to Marshall thread which I was not able to solve even after using Dispather helper

Answer 1

你能去掉这个选项吗

IndexerOption = IndexerOption.OnlyUseIndexerAndOptimizeForIndexedProperties

来自函数 GetVideoFoldersQuery，因此看起来像这样

internal static StorageFolderQueryResult GetVideoFoldersQuery(StorageFolder Folder, uint thumbnailRequestedSize)
{
    if (videoFolderOptions is null)
    {
        videoFolderOptions = new QueryOptions(CommonFolderQuery.DefaultQuery);
        videoFolderOptions.SetThumbnailPrefetch(ThumbnailMode.VideosView, thumbnailRequestedSize, ThumbnailOptions.UseCurrentScale);
    }
    return Folder.CreateFolderQueryWithOptions(videoFolderOptions);
}

对于这个版本，我发现它不会崩溃并出现与以前相同的错误。

我确实在函数 GetDisplayForFile 中遇到了 InvalidCastException，但我认为这是完全不同的问题。

编辑

我将以下测试代码块插入到您代码中的 OnNavigateTo 函数中：

var    folder = KnownFolders.VideosLibrary;

// Define two different QueryOptions
var    qo_1   = new QueryOptions(CommonFolderQuery.DefaultQuery);
var    qo_2   = new QueryOptions(CommonFolderQuery.DefaultQuery)
                    {
                      IndexerOption = IndexerOption.OnlyUseIndexerAndOptimizeForIndexedProperties
                    };

// Query folder and then query the files and subfolders
// using the first QueryOptions qo_1
var    fq_1   = folder.CreateFolderQueryWithOptions ( qo_1 ) ;
var    fo_1   = await fq_1.GetFoldersAsync ( 0, 5 ) ;
foreach ( var subfold in fo_1 )
{
  var f_1  = subfold.CreateFileQueryWithOptions ( qo_1 ) ;
  var sf_1 = subfold.CreateFolderQueryWithOptions ( qo_1 ) ;
}

// Query folder and then query the files and subfolders
// using the first QueryOptions qo_2
var    fq_2   = folder.CreateFolderQueryWithOptions ( qo_2 ) ;
var    fo_2   = await fq_2.GetFoldersAsync ( 0, 5 ) ;
foreach ( var subfold in fo_2 )
{
  var f_2  = subfold.CreateFileQueryWithOptions ( qo_2 ) ;
  var sf_2 = subfold.CreateFolderQueryWithOptions ( qo_2 ) ;
}

它定义了两个不同的 QueryOption 对象，然后对每个对象执行二级查询。

第一个工作正常。
第二个在第二级查询时崩溃。

我认为这是一个错误，您应该向 Microsoft 报告。您可能会在 Microsoft 论坛中获得更多帮助。

CreateQueryWithOptions 导致系统互操作 Com 异常

CreateQueryWithOptions causes system interop Com exception

c#

uwp

com-interop

uwp-xaml

video-library

我的 ViewModel 中的 FillFolders 方法**