WindowsRuntimeStorageExtensions 类

  • 参考

定义

命名空间:
System.IO
程序集:
System.Runtime.WindowsRuntime.dll

在开发 Windows 应用商店应用程序时，将 IStorageFile 和 IStorageFolder 接口的扩展方法包含在 Windows 运行时中。

public ref class WindowsRuntimeStorageExtensions abstract sealed
public static class WindowsRuntimeStorageExtensions
[System.Security.SecurityCritical]
public static class WindowsRuntimeStorageExtensions
type WindowsRuntimeStorageExtensions = class
[<System.Security.SecurityCritical>]
type WindowsRuntimeStorageExtensions = class
Public Module WindowsRuntimeStorageExtensions
继承
Object
WindowsRuntimeStorageExtensions
属性
SecurityCriticalAttribute

示例

以下示例演示如何在应用程序数据中以 Windows Store 应用中的形式Stream打开文件，并使用类的StreamWriter实例写入该文件。 然后，它通过使用类的 StreamReader 实例读取文件的内容。

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

namespace ExampleApplication
{
    public sealed partial class BlankPage : Page
    {
        public BlankPage()
        {
            this.InitializeComponent();
        }

        private async void CreateButton_Click(object sender, RoutedEventArgs e)
        {
            using (StreamWriter writer =
                new StreamWriter(await ApplicationData.Current.LocalFolder.OpenStreamForWriteAsync(
                "testfile.txt",  CreationCollisionOption.OpenIfExists)))
            {
                await writer.WriteLineAsync("new entry");
                await writer.WriteLineAsync(UserText.Text);
            }
        }

        private async void VerifyButton_Click(object sender, RoutedEventArgs e)
        {
            StorageFile openedFile = await ApplicationData.Current.LocalFolder.GetFileAsync("testfile.txt");
            using (StreamReader reader = new StreamReader(await openedFile.OpenStreamForReadAsync()))
            {
                Results.Text = await reader.ReadToEndAsync();
            }
        }
    }
}

Imports System.IO
Imports Windows.Storage

NotInheritable Public Class BlankPage
    Inherits Page

    Private Async Sub CreateButton_Click(sender As Object, e As RoutedEventArgs)
        Using writer As StreamWriter =
               New StreamWriter(Await ApplicationData.Current.LocalFolder.OpenStreamForWriteAsync(
               "testfile.txt", CreationCollisionOption.OpenIfExists))
            Await writer.WriteLineAsync("new entry")
            Await writer.WriteLineAsync(UserText.Text)
        End Using
    End Sub

    Private Async Sub VerifyButton_Click(sender As Object, e As RoutedEventArgs)
        Dim openedFile As StorageFile = Await ApplicationData.Current.LocalFolder.GetFileAsync("testfile.txt")
        Using reader As StreamReader = New StreamReader(Await openedFile.OpenStreamForReadAsync())
            Results.Text = Await reader.ReadToEndAsync()
        End Using
    End Sub
End Class

下一个示例显示与上一个示例关联的 XAML 代码。

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

    <StackPanel Background="{StaticResource ApplicationPageBackgroundBrush}" VerticalAlignment="Center" HorizontalAlignment="Center">
        <TextBlock Text="Provide text to write to file:"></TextBlock>
        <TextBox Name="UserText" Width="400"></TextBox>
        <Button Name="CreateButton" Content="Create File" Click="CreateButton_Click"></Button>
        <Button Name="VerifyButton" Content="Verify Contents" Click="VerifyButton_Click"></Button>
        <TextBlock Name="Results"></TextBlock>
    </StackPanel>
</Page>

注解

仅当你开发 Windows 应用商店应用时，这些扩展方法才可用。 这些方法提供了在 Windows 应用商店应用中打开文件以读取或写入的便捷方法。 不创建类的WindowsRuntimeStorageExtensions实例;而是从接口的IStorageFileIStorageFolder实例使用这些方法。

该 WindowsRuntimeStorageExtensions 类包含两种扩展 IStorageFile 用于读取或写入的方法：

WindowsRuntimeStorageExtensions 类包含两种扩展 IStorageFolder 用于读取和写入的方法：

方法

CreateSafeFileHandle(IStorageFile, FileAccess, FileShare, FileOptions)

为当前存储文件实例创建安全文件句柄。
CreateSafeFileHandle(IStorageFolder, String, FileMode)

为当前存储文件夹实例中的文件创建安全文件句柄。
CreateSafeFileHandle(IStorageFolder, String, FileMode, FileAccess, FileShare, FileOptions)

为当前存储文件夹实例中的文件创建安全文件句柄。
OpenStreamForReadAsync(IStorageFile)

检索流以从指定的文件中读取。
OpenStreamForReadAsync(IStorageFolder, String)

检索流以从指定的父文件夹的一个文件中读取。
OpenStreamForWriteAsync(IStorageFile)

检索流以写入指定的文件。
OpenStreamForWriteAsync(IStorageFolder, String, CreationCollisionOption)

检索流以在指定的父文件夹中写入文件。

适用于