WindowsRuntimeStreamExtensions.AsOutputStream(Stream) Метод

Определение

Важно!

Этот API несовместим с CLS.

Преобразует управляемый поток в .NET для приложений Магазина Windows в поток вывода в среде выполнения Windows.Converts a managed stream in the .NET for Windows Store apps to an output stream in the Windows Runtime.

public:
[System::Runtime::CompilerServices::Extension]
 static Windows::Storage::Streams::IOutputStream ^ AsOutputStream(System::IO::Stream ^ stream);
[System.CLSCompliant(false)]
public static Windows.Storage.Streams.IOutputStream AsOutputStream (this System.IO.Stream stream);
static member AsOutputStream : System.IO.Stream -> Windows.Storage.Streams.IOutputStream
<Extension()>
Public Function AsOutputStream (stream As Stream) As IOutputStream

Параметры

stream
Stream

Поток для преобразования.The stream to convert.

Возвращаемое значение

IOutputStream

Объект IOutputStream среды выполнения Windows, представляющий преобразованный поток.A Windows Runtime IOutputStream object that represents the converted stream.

Атрибуты

Исключения

Параметр stream равен null.stream is null.

Поток не поддерживает чтение.The stream does not support reading.

Примеры

В следующем примере показано, как использовать методы AsInputStream и AsOutputStream> для преобразования управляемого потока в поток в среда выполнения Windows и из него.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

Ниже приведен код XAML, связанный с предыдущим примером.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>

Комментарии

Примечание

В Visual Basic и C#этот метод можно вызвать как метод экземпляра для любого объекта типа Stream.In Visual Basic and C#, you can call this method as an instance method on any object of type Stream. При вызове метода для экземпляра следует опускать первый параметр.When you use instance method syntax to call this method, omit the first parameter. Дополнительные сведения см. в разделе методы расширения (Visual Basic) или методы расширенияC# (руководством по программированию).For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

Применяется к