Windows 8 Store Apps學習(22) 檔案系統: 訪問檔案夾和檔案,搜尋本地檔案

檔案系統: 訪問檔案夾和檔案, 通過 AQS 搜尋本地檔案

介紹

重新想象 Windows 8 Store Apps 之 檔案系統

File Access - 訪問檔案夾和檔案，以及擷取檔案的各種屬性

Folder Access - 遍曆檔案夾時的一些特殊操作

Thumbnail Access - 擷取檔案的縮圖

AQS - 通過 AQS（Advanced Query Syntax）搜尋本地檔案

樣本

1、示範如何訪問檔案夾和檔案，以及如何擷取檔案的各種屬性

FileSystem/FileAccess.xaml

<Page    x:Class="XamlDemo.FileSystem.FileAccess"    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"    xmlns:local="using:XamlDemo.FileSystem"    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="120 0 0 0">                <TextBlock Name="lblMsg" FontSize="14.667" />                         <ListBox Name="listBox" Width="400" Height="200" SelectionChanged="listBox_SelectionChanged_1" HorizontalAlignment="Left" Margin="0 10 0 0" />                        </StackPanel>    </Grid></Page>

FileSystem/FileAccess.xaml.cs

/* * 示範如何訪問檔案夾和檔案，以及如何擷取檔案的各種屬性 *  * StorageFolder - 檔案夾操作類 *     擷取檔案夾相關屬性、重新命名、Create...、Get...等 *  * StorageFile - 檔案操作類 *     擷取檔案相關屬性、重新命名、Create...、Get...、Copy...、Move...、Delete...、Open...、Replace...等 *      * 註：WinRT 中的關於儲存操作的相關類都在 Windows.Storage 命名空間內 */    using System;using System.Collections.Generic;using Windows.Storage;using Windows.Storage.FileProperties;using Windows.UI.Xaml;using Windows.UI.Xaml.Controls;using Windows.UI.Xaml.Navigation;using System.Linq;    namespace XamlDemo.FileSystem{    public sealed partial class FileAccess : Page    {        public FileAccess()        {            this.InitializeComponent();        }            protected async override void OnNavigatedTo(NavigationEventArgs e)        {            // 遍曆“文件庫”目錄下的所有頂級檔案（需要在 Package.appxmanifest 中選中“文件庫”功能）            StorageFolder storageFolder = KnownFolders.DocumentsLibrary;            IReadOnlyList<StorageFile> files = await storageFolder.GetFilesAsync();            listBox.ItemsSource = files.Select(p => p.Name).ToList();        }            private async void listBox_SelectionChanged_1(object sender, SelectionChangedEventArgs e)        {            // 擷取使用者選中的檔案            string fileName = (string)listBox.SelectedItem;            StorageFolder storageFolder = KnownFolders.DocumentsLibrary;            StorageFile storageFile = await storageFolder.GetFileAsync(fileName);                // 顯示檔案的各種屬性            if (storageFile != null)            {                lblMsg.Text = "Name：" + storageFile.Name;                lblMsg.Text += Environment.NewLine;                lblMsg.Text += "FileType：" + storageFile.FileType;                lblMsg.Text += Environment.NewLine;                    BasicProperties basicProperties = await storageFile.GetBasicPropertiesAsync();                lblMsg.Text += "Size：" + basicProperties.Size;                lblMsg.Text += Environment.NewLine;                lblMsg.Text += "DateModified：" + basicProperties.DateModified;                lblMsg.Text += Environment.NewLine;                    /*                 * 擷取檔案的其它各種屬性                 * 詳細屬性列表請參見：http://msdn.microsoft.com/en-us/library/windows/desktop/ff521735(v=vs.85).aspx                 */                List<string> propertiesName = new List<string>();                propertiesName.Add("System.DateAccessed");                propertiesName.Add("System.DateCreated");                propertiesName.Add("System.FileOwner");                IDictionary<string, object> extraProperties = await storageFile.Properties.RetrievePropertiesAsync(propertiesName);                    lblMsg.Text += "System.DateAccessed：" + extraProperties["System.DateAccessed"];                lblMsg.Text += Environment.NewLine;                lblMsg.Text += "System.DateCreated：" + extraProperties["System.DateCreated"];                lblMsg.Text += Environment.NewLine;                lblMsg.Text += "System.FileOwner：" + extraProperties["System.FileOwner"];            }        }    }}

2、示範遍曆檔案夾時的一些特殊操作

FileSystem/FolderAccess.xaml

<Page    x:Class="XamlDemo.FileSystem.FolderAccess"    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"    xmlns:local="using:XamlDemo.FileSystem"    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="120 0 0 0">                <TextBlock Name="lblMsg" FontSize="14.667" />                <Button Name="btnGroupFile" Content="分組檔案" Click="btnGroupFile_Click_1" Margin="0 10 0 0" />                <Button Name="btnPrefetchAPI" Content="從 Prefetch 中載入資訊" Click="btnPrefetchAPI_Click_1" Margin="0 10 0 0" />                        </StackPanel>    </Grid></Page>