WindowsRuntimeStreamExtensions.AsInputStream(Stream) 方法

定義

命名空間:

System.IO

組件:

System.Runtime.WindowsRuntime.dll

重要

此 API 不符合 CLS 規範。

將適用於 Windows 市集應用程式的 .NET 中的受控資料流轉換成 Windows 執行階段中的輸入資料流。

public:
[System::Runtime::CompilerServices::Extension]
 static Windows::Storage::Streams::IInputStream ^ AsInputStream(System::IO::Stream ^ stream);

[System.CLSCompliant(false)]
public static Windows.Storage.Streams.IInputStream AsInputStream (this System.IO.Stream stream);

[<System.CLSCompliant(false)>]
static member AsInputStream : System.IO.Stream -> Windows.Storage.Streams.IInputStream

<Extension()>
Public Function AsInputStream (stream As Stream) As IInputStream

參數

stream

Stream

要轉換的資料流。

傳回

IInputStream

代表已轉換之資料流的 Windows 執行階段 IInputStream 物件。

屬性

CLSCompliantAttribute

例外狀況

ArgumentNullException

stream 為 null。

NotSupportedException

資料流不支援讀取。

範例

下列範例示範如何使用 AsInputStream 和 AsOutputStream 方法，將 Managed 資料流程轉換成 Windows 執行階段 中的資料流程。

using System;
using System.IO;
using System.Text;
using Windows.Storage;
using Windows.Storage.Streams;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;

namespace ExampleApplication
{
    public sealed partial class BlankPage : Page
    {
        System.Text.UnicodeEncoding ue;
        byte[] bytesToWrite;
        byte[] bytesToAdd;
        int totalBytes;

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

        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
            ue = new System.Text.UnicodeEncoding();
            bytesToWrite = ue.GetBytes("example text to write to memory stream");
            bytesToAdd = ue.GetBytes("text added through datawriter");
            totalBytes = bytesToWrite.Length + bytesToAdd.Length;
        }

        private async void CreateButton_Click(object sender, RoutedEventArgs e)
        {
            byte[] bytesRead = new byte[totalBytes];
            using (MemoryStream memStream = new MemoryStream(totalBytes))
            {
                await memStream.WriteAsync(bytesToWrite, 0, bytesToWrite.Length);

                DataWriter writer = new DataWriter(memStream.AsOutputStream());
                writer.WriteBytes(bytesToAdd);
                await writer.StoreAsync();

                memStream.Seek(0, SeekOrigin.Begin);

                DataReader reader = new DataReader(memStream.AsInputStream());
                await reader.LoadAsync((uint)totalBytes);
                reader.ReadBytes(bytesRead);
                Results.Text = ue.GetString(bytesRead, 0, bytesRead.Length);
            }
        }
    }
}

Imports Windows.Storage.Streams

Public NotInheritable Class BlankPage
    Inherits Page

    Dim ue As System.Text.UnicodeEncoding
    Dim bytesToWrite() As Byte
    Dim bytesToAdd() As Byte
    Dim totalBytes As Integer


    Protected Overrides Sub OnNavigatedTo(e As Navigation.NavigationEventArgs)
        ue = New System.Text.UnicodeEncoding()
        bytesToWrite = ue.GetBytes("example text to write to memory stream")
        bytesToAdd = ue.GetBytes("text added through datawriter")
        totalBytes = bytesToWrite.Length + bytesToAdd.Length
    End Sub

    Private Async Sub CreateButton_Click(sender As Object, e As RoutedEventArgs)
        Dim bytesRead(totalBytes - 1) As Byte
        Using memStream As MemoryStream = New MemoryStream(totalBytes)
            Await memStream.WriteAsync(bytesToWrite, 0, bytesToWrite.Length)

            Dim writer As DataWriter = New DataWriter(memStream.AsOutputStream())
            writer.WriteBytes(bytesToAdd)
            Await writer.StoreAsync()

            memStream.Seek(0, SeekOrigin.Begin)

            Dim reader As DataReader = New DataReader(memStream.AsInputStream())
            Await reader.LoadAsync(CType(totalBytes, UInteger))
            reader.ReadBytes(bytesRead)
            Results.Text = ue.GetString(bytesRead, 0, bytesRead.Length)
        End Using
    End Sub
End Class

以下是與上一個範例相關聯的 XAML 程式碼。

<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">
        <Button Name="CreateButton" Content="Write and read with stream" Click="CreateButton_Click"></Button>
        <TextBlock Name="Results"></TextBlock>
    </StackPanel>
</Page>

備註

注意

在 Visual Basic 和 C# 中，您可以在類型 Stream 的任何物件上呼叫這個方法作為實例方法。 使用執行個體方法語法呼叫這個方法時，請省略第一個參數。 如需詳細資訊，請參閱 Visual Basic) (擴充方法 或 C# 程式設計手冊 (的擴充方法) 。