WindowsRuntimeStreamExtensions.AsInputStream(Stream) Méthode

Référence

Définition

Espace de noms:: System.IO

Assembly:: System.Runtime.WindowsRuntime.dll

Important

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Important

Cette API n’est pas conforme CLS.

Convertit un flux managé dans .NET pour les applications du Windows Store en un flux d’entrée 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

Paramètres

stream: Stream

Flux à convertir.

Retours

IInputStream

Objet IInputStream Windows Runtime qui représente le flux converti.

Attributs: CLSCompliantAttribute

Exceptions

ArgumentNullException

stream a la valeur null.

NotSupportedException

Le flux ne prend pas en charge la lecture.

Exemples

L’exemple suivant montre comment utiliser les AsInputStream méthodes et AsOutputStream pour convertir un flux managé vers et à partir d’un flux dans le Windows Runtime.

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

Voici le code XAML associé à l’exemple précédent.

<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>

Remarques

Notes

Dans Visual Basic et C#, vous pouvez appeler cette méthode en tant que méthode instance sur n’importe quel objet de type Stream. Lorsque vous utilisez la syntaxe des méthodes d'instance pour appeler cette méthode, omettez le premier paramètre. Pour plus d’informations, consultez Méthodes d’extension (Visual Basic) ou Méthodes d’extension (Guide de programmation C#).

S’applique à

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