WindowsRuntimeStreamExtensions.AsInputStream(Stream) Metoda

Definicja

Ważne

Ten interfejs API nie jest zgodny ze specyfikacją CLS.

Konwertuje zarządzany strumień w programie .NET dla aplikacji do sklepu Windows na strumień wejściowy w środowisko wykonawcze systemu Windows.Converts a managed stream in the .NET for Windows Store apps to an input stream in the 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);
static member AsInputStream : System.IO.Stream -> Windows.Storage.Streams.IInputStream

Parametry

stream
Stream

Strumień do przekonwertowania.The stream to convert.

Zwraca

Obiekt środowisko wykonawcze systemu Windows IInputStream , który reprezentuje przekonwertowany strumień.A Windows Runtime IInputStream object that represents the converted stream.

Atrybuty

Wyjątki

streamjest null.stream is null.

Strumień nie obsługuje odczytywania.The stream does not support reading.

Przykłady

Poniższy przykład pokazuje, AsInputStream jak używać metod i AsOutputStream do konwertowania zarządzanego strumienia do i ze strumienia w środowisko wykonawcze systemu Windows.The following example shows how to use the AsInputStream and AsOutputStream methods to convert a managed stream to and from a stream in the 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

Oto kod XAML, który jest skojarzony z poprzednim przykładem.Here's the XAML code that is associated with the previous example.

<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>

Uwagi

Uwaga

W Visual Basic i C#można wywołać tę metodę jako metodę wystąpienia dla dowolnego obiektu typu Stream.In Visual Basic and C#, you can call this method as an instance method on any object of type Stream. Gdy w celu wywołania tej metody jest używana składnia metody wystąpienia, należy pominąć pierwszy parametr.When you use instance method syntax to call this method, omit the first parameter. Aby uzyskać więcej informacji, zobacz metody rozszerzania (Visual Basic) lub metodyC# rozszerzenia (Przewodnik programowania).For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

Dotyczy