Question

我正在使用Windows.Storage GetFilesAsync函数检索文件信息，但是发现文件计数通常不正确（与OS属性相比）。奇怪的是，有时这个数字小于操作系统的数量，而有时却大于操作系统的数量！？

我创建了一个迷你项目来复制问题。在文件数量很少的文件夹中，它们确实可以匹配，但在文件数量较大（即500以上）的文件夹中，计数通常会很远。

要进行复制，请创建一个通用Windows空白应用程序，然后将其复制到MainPage.xaml：

<Page
x:Class="TestFileCount.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:TestFileCount"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">

<Grid>
    <Button Name="btnSelect" Content="Select Folder" HorizontalAlignment="Left" Height="195" Margin="254,412,0,0" VerticalAlignment="Top" Width="805" Click="btnSelect_Click"/>
    <TextBlock Name="txtFolder" HorizontalAlignment="Left" Height="92" Margin="185,212,0,0" Text="" TextWrapping="Wrap" VerticalAlignment="Top" Width="1156"/>
    <TextBlock Name="txtResult"  HorizontalAlignment="Left" Height="163" Margin="96,701,0,0" Text="" TextWrapping="Wrap" VerticalAlignment="Top" Width="1210"/>

</Grid>

最后将其复制到MainPage.xaml.cs并运行应用程序：

using System;
using System.Collections.Generic;
using Windows.Storage;
using Windows.Storage.FileProperties;
using Windows.Storage.Search;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;


namespace TestFileCount
{
    public sealed partial class MainPage : Page
    {
      public MainPage()
      {
        this.InitializeComponent();
    }

    private async void btnSelect_Click(object sender, RoutedEventArgs e)
    {

        const string SizeProperty = "System.Size";
        const string DateModProperty = "System.DateModified";

        var folderPicker = new Windows.Storage.Pickers.FolderPicker
        {
            SuggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.Desktop
        };

        folderPicker.FileTypeFilter.Add("*");


        StorageFolder folder = await folderPicker.PickSingleFolderAsync();

        //cancelled
        if (folder == null)
        {
            return;
        }

        txtResult.Text = "Processing...";
        txtFolder.Text = folder.Path;
        btnSelect.IsEnabled = false;

        // Set up file settings
        List<string> fileTypeFilter = new List<string>();
        List<string> propertyNames = new List<string>
        {
            SizeProperty,
            DateModProperty
        };

        // Create query options
        QueryOptions queryOptions = new QueryOptions(CommonFileQuery.OrderByName, fileTypeFilter)
        {
            FolderDepth = FolderDepth.Deep,
            IndexerOption = IndexerOption.UseIndexerWhenAvailable
        };
        queryOptions.SetPropertyPrefetch(PropertyPrefetchOptions.BasicProperties, propertyNames);

        StorageFileQueryResult query = folder.CreateFileQueryWithOptions(queryOptions);

        //get files
        IReadOnlyList<StorageFile> fileList = await query.GetFilesAsync();

        txtResult.Text = fileList.Count.ToString();
        btnSelect.IsEnabled = true;
    }
  }
}

Answer 1

这似乎是一个已知问题，由于OrderByName，它不起作用。删除OrderByName。

QueryOptions queryOptions = new QueryOptions(){...};

提到here时，它与库文件夹之外的其他文档均相反，该文档指出它在任何地方都可以使用。即使我在PC上对其进行了测试，但效果很好。

Windows.Storage函数返回错误的文件计数

1 个答案: