背水一战 Windows 10 (90) - 文件系统: 获取 Package 中的文件, 可移动存储中的文件操作, “库”管理

Posted 2020-11-17 webabcd

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背水一战 Windows 10 (90) - 文件系统: 获取 Package 中的文件, 可移动存储中的文件操作, “库”管理

作者：webabcd


介绍
背水一战 Windows 10 之 文件系统

• 获取 Package 中的文件
• 可移动存储中的文件操作
• “库”管理

示例
1、演示如何获取 Package 中的文件
FileSystem/PackageData/Demo.xaml

<Page
    x:Class="Windows10.FileSystem.PackageData.Demo"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:Windows10.FileSystem.PackageData"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

    <Grid Background="Transparent">
        <StackPanel Margin="10 0 10 10">

            <TextBlock Name="lblMsg" Margin="5" />

            <Button Name="btnRead" Content="读取 Package 中的文件" Click="btnRead_Click" Margin="5" />

            <Image Name="img" Stretch="None" HorizontalAlignment="Left" Margin="5" />

        </StackPanel>
    </Grid>
</Page>

FileSystem/PackageData/Demo.xaml.cs

/*
 * 演示如何获取 Package 中的文件
 * 1、可以通过 Package.Current.InstalledLocation.GetFileAsync() 访问
 * 2、可以通过 ms-appx:/// 访问
 * 
 * 
 * StorageFile - 文件操作类
 *     public static IAsyncOperation<StorageFile> GetFileFromApplicationUriAsync(Uri uri) - 获取本地指定 uri 的文件
 *     
 *     
 * 注：需要访问的 Package 中的文件的属性的“生成操作”应该设置为“内容”
 */

using System;
using Windows.Storage;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;

namespace Windows10.FileSystem.PackageData
{
    public sealed partial class Demo : Page
    {
        public Demo()
        {
            this.InitializeComponent();
        }

        private async void btnRead_Click(object sender, RoutedEventArgs e)
        {
            // 写（无法向程序包中写数据，会报错）
            // StorageFile fileWrite = await Package.Current.InstalledLocation.CreateFileAsync(@"FileSystemPackageData
eadWriteDemo.txt", CreationCollisionOption.ReplaceExisting);
            // await FileIO.WriteTextAsync(fileWrite, "I am webabcd: " + DateTime.Now.ToString());

            // 读
            // StorageFile fileRead = await Package.Current.InstalledLocation.GetFileAsync(@"FileSystemPackageData
eadWriteDemo.txt");
            StorageFile fileRead = await StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appx:///FileSystem/PackageData/readWriteDemo.txt", UriKind.Absolute));
            string textContent = await FileIO.ReadTextAsync(fileRead);
            lblMsg.Text = textContent;


            // 引用程序包内的图片文件并显示
            img.Source = new Windows.UI.Xaml.Media.Imaging.BitmapImage(new Uri("ms-appx:///Assets/hololens.jpg"));
        }
    }
}

2、演示如何在可移动存储中对文件进行操作
FileSystem/RemovableDevice/Demo.xaml

<Page
    x:Class="Windows10.FileSystem.RemovableDevice.Demo"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:Windows10.FileSystem.RemovableDevice"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

    <Grid Background="Transparent">
        <StackPanel Margin="10 0 10 10">

            <TextBlock Name="lblMsg" Margin="5" />

            <ListBox Name="listBox" Width="400" Height="200" HorizontalAlignment="Left" Margin="5" SelectionChanged="listBox_SelectionChanged" />

            <Button Name="btnCopyFile" Content="复制文件到当前选中的设备中" Margin="5" Click="btnCopyFile_Click" />

        </StackPanel>
    </Grid>
</Page>

FileSystem/RemovableDevice/Demo.xaml.cs

/*
 * 演示如何在可移动存储中对文件进行操作
 */

using System;
using System.Collections.Generic;
using System.Linq;
using Windows.Storage;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;

namespace Windows10.FileSystem.RemovableDevice
{
    public sealed partial class Demo : Page
    {
        public Demo()
        {
            this.InitializeComponent();
        }

        protected async override void OnNavigatedTo(NavigationEventArgs e)
        {
            // 获取全部可移动存储
            StorageFolder removableDevices = await KnownFolders.GetFolderForUserAsync(null, KnownFolderId.RemovableDevices);
            IReadOnlyList<StorageFolder> folderList = await removableDevices.GetFoldersAsync();
            listBox.ItemsSource = folderList.Select(p => p.Name).ToList();

            base.OnNavigatedTo(e);
        }

        private async void listBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            // 用户选中的可移动存储
            string folderName = (string)listBox.SelectedItem;
            StorageFolder removableDevices = await KnownFolders.GetFolderForUserAsync(null, KnownFolderId.RemovableDevices);
            StorageFolder storageFolder = await removableDevices.GetFolderAsync(folderName);

            // 用户选中的可移动存储中的根目录下的文件和文件夹总数
            IReadOnlyList<IStorageItem> storageItems = await storageFolder.GetItemsAsync();
            lblMsg.Text = "items count: " + storageItems.Count;
        }
        
        private async void btnCopyFile_Click(object sender, RoutedEventArgs e)
        {
            // 用户选中的可移动存储
            string folderName = (string)listBox.SelectedItem;

            if (folderName != null)
            {
                StorageFolder removableDevices = await KnownFolders.GetFolderForUserAsync(null, KnownFolderId.RemovableDevices);
                StorageFolder storageFolder = await removableDevices.GetFolderAsync(folderName);

                // 复制包内文件到指定的可移动存储
                StorageFile storageFile = await StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appx:///Assets/hololens.jpg"));
                try
                {
                    await storageFile.CopyAsync(storageFolder, "hololens.jpg", NameCollisionOption.ReplaceExisting);
                    lblMsg.Text = "复制成功";
                }
                catch (Exception ex)
                {
                    lblMsg.Text = ex.ToString();
                }
            }
        }
    }
}

3、演示如何 添加/删除 “库”所包含的文件夹
FileSystem/StorageLibrary/StorageLibraryDemo.xaml

<Page
    x:Class="Windows10.FileSystem.StorageLibrary.StorageLibraryDemo"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:Windows10.FileSystem.StorageLibrary"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

    <Grid Background="Transparent">

        <StackPanel Margin="10 0 10 10">

            <TextBlock Name="lblMsg" Margin="5" />

            <Button Name="btnAddFolder" Content="增加一个文件夹引用到图片库" Click="btnAddFolder_Click" Margin="5" />

            <Button Name="btnRemoveFolder" Content="从图片库移除之前添加的全部文件夹引用" Click="btnRemoveFolder_Click" Margin="5" />

        </StackPanel>
    </Grid>
</Page>

FileSystem/StorageLibrary/StorageLibraryDemo.xaml.cs

/*
 * 演示如何 添加/删除 “库”所包含的文件夹
 * 
 * StorageLibrary - 用于“库”管理
 *     GetLibraryForUserAsync(User user, KnownLibraryId libraryId) - 获取指定用户的指定“库”，返回 StorageLibrary 类型的对象
 *         user - 指定用户，传 null 则为当前用户（关于 User 相关请参见 /UserAndAccount/UserInfo.xaml）
 *         libraryId - 指定库目录，一个 KnownLibraryId 类型的枚举值（Music, Pictures, Videos, Documents）
 *     Folders - 当前库所包含的文件夹们
 *     SaveFolder - 当前库的默认文件夹
 *     RequestAddFolderAsync() - 添加文件夹到当前库
 *     RequestRemoveFolderAsync() - 从当前库移除指定的文件夹
 *     DefinitionChanged -  当前库所包含的文件夹发生变化时触发的事件
 *     
 *     
 * 注：根据需要请在 Package.appxmanifest 中配置  <Capability Name="picturesLibrary" />, <Capability Name="videosLibrary" />,  <Capability Name="musicLibrary" />, <Capability Name="documentsLibrary" />
 */

using System;
using System.Collections.Generic;
using Windows.Storage;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;

namespace Windows10.FileSystem.StorageLibrary
{
    public sealed partial class StorageLibraryDemo : Page
    {
        // 临时保存添加进图片库的文件夹
        private List<StorageFolder> _addedFloders = new List<StorageFolder>();

        public StorageLibraryDemo()
        {
            this.InitializeComponent();
        }

        protected async override void OnNavigatedTo(NavigationEventArgs e)
        {
            // 注意：要想访问图片库，别忘了增加 <Capability Name="picturesLibrary" />

            // 获取图片库的 StorageLibrary 对象
            Windows.Storage.StorageLibrary picturesLibrary = await Windows.Storage.StorageLibrary.GetLibraryForUserAsync(null, KnownLibraryId.Pictures);

            // 当前库所包含的文件夹增多或减少时
            picturesLibrary.DefinitionChanged += async (Windows.Storage.StorageLibrary innerSender, object innerEvent) =>
            {
                await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
                {
                    lblMsg.Text = "图片库所包含的文件夹如下：";
                    foreach (StorageFolder folder in picturesLibrary.Folders) // 当前库所包含的全部文件夹
                    {
                        lblMsg.Text += Environment.NewLine;
                        lblMsg.Text += folder.Path;
                    }
                });
            };

            base.OnNavigatedTo(e);
        }

        // 增加一个文件夹引用到图片库
        private async void btnAddFolder_Click(object sender, RoutedEventArgs e)
        {
            Windows.Storage.StorageLibrary picturesLibrary = await Windows.Storage.StorageLibrary.GetLibraryAsync(KnownLibraryId.Pictures);

            // 弹出文件夹选择器，以选择需要添加到图片库的文件夹
            StorageFolder addedFolder = await picturesLibrary.RequestAddFolderAsync();
            if (addedFolder != null)
            {
                // 添加成功
                _addedFloders.Add(addedFolder);
            }
            else
            {

            }
        }

        // 从图片库移除之前添加的全部文件夹引用
        private async void btnRemoveFolder_Click(object sender, RoutedEventArgs e)
        {
            Windows.Storage.StorageLibrary picturesLibrary = await Windows.Storage.StorageLibrary.GetLibraryAsync(KnownLibraryId.Pictures);

            foreach (StorageFolder folder in _addedFloders)
            {
                // 从图片库移除指定的文件夹引用
                if (await picturesLibrary.RequestRemoveFolderAsync(folder))
                {
                    // 移除成功
                }
                else
                {

                }
            }
        }
    }
}

OK
[源码下载]