WindowsRuntimeStreamExtensions.AsInputStream(Stream) Methode

Definition

Namespace:

System.IO

Assembly:

System.Runtime.WindowsRuntime.dll

Wichtig

Diese API ist nicht CLS-kompatibel.

Konvertiert einen verwalteten Stream in .NET für Microsoft Store-Apps in einen Eingabestream in der Windows-Runtime.

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

Parameter

stream

Stream

Der zu konvertierende Stream.

Gibt zurück

IInputStream

Ein Windows-Runtime-IInputStream-Objekt, das den konvertierten Stream darstellt.

Attribute

CLSCompliantAttribute

Ausnahmen

ArgumentNullException

stream ist null.

NotSupportedException

Lesevorgänge werden vom Stream nicht unterstützt.

Beispiele

Das folgende Beispiel zeigt, wie Sie die AsInputStream Methoden und AsOutputStream verwenden, um einen verwalteten Stream in einen und aus einem Stream im Windows-Runtime zu konvertieren.

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

Hier sehen Sie den XAML-Code, der dem vorherigen Beispiel zugeordnet ist.

<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>

Hinweise

Hinweis

In Visual Basic und C# können Sie diese Methode als Instanzmethode für jedes Objekt des Typs Streamaufrufen. Bei Verwendung der Syntax für Instanzenmethoden lassen Sie den ersten Parameter aus. Weitere Informationen finden Sie unter Erweiterungsmethoden (Visual Basic) oder Erweiterungsmethoden (C#-Programmierhandbuch).