Bagikan melalui

WindowsRuntimeStorageExtensions.OpenStreamForWriteAsync Metode

  • Referensi

Definisi

Ruang nama:
System.IO
Rakitan:
System.Runtime.WindowsRuntime.dll

Overload

OpenStreamForWriteAsync(IStorageFile)

Mengambil aliran untuk menulis ke file tertentu.
OpenStreamForWriteAsync(IStorageFolder, String, CreationCollisionOption)

Mengambil aliran untuk menulis ke file di folder induk yang ditentukan.

OpenStreamForWriteAsync(IStorageFile)

Penting

API ini bukan kompatibel CLS.

Mengambil aliran untuk menulis ke file tertentu.

public:
[System::Runtime::CompilerServices::Extension]
 static System::Threading::Tasks::Task<System::IO::Stream ^> ^ OpenStreamForWriteAsync(Windows::Storage::IStorageFile ^ windowsRuntimeFile);
[System.CLSCompliant(false)]
public static System.Threading.Tasks.Task<System.IO.Stream> OpenStreamForWriteAsync (this Windows.Storage.IStorageFile windowsRuntimeFile);
[<System.CLSCompliant(false)>]
static member OpenStreamForWriteAsync : Windows.Storage.IStorageFile -> System.Threading.Tasks.Task<System.IO.Stream>
<Extension()>
Public Function OpenStreamForWriteAsync (windowsRuntimeFile As IStorageFile) As Task(Of Stream)

Parameter

windowsRuntimeFile
IStorageFile

Objek Windows Runtime IStorageFile untuk ditulis.

Mengembalikan

Task<Stream>

Tugas yang mewakili operasi penulisan asinkron.

Atribut
CLSCompliantAttribute

Pengecualian

ArgumentNullException

windowsRuntimeFileadalah null.

IOException

File tidak dapat dibuka atau diambil sebagai aliran.

Contoh

Contoh berikut menunjukkan cara membuka file sebagai Stream di aplikasi Bursa Windows, dan menulisnya dengan menggunakan instans StreamReader kelas .

using System;
using System.IO;
using Windows.Storage;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;

namespace ExampleApplication
{
    public sealed partial class BlankPage : Page
    {
        public BlankPage()
        {
            this.InitializeComponent();
        }

        private async void CreateButton_Click(object sender, RoutedEventArgs e)
        {
            StorageFile newFile = await ApplicationData.Current.LocalFolder.CreateFileAsync("testfile3.txt");

            using (StreamWriter writer = new StreamWriter(await newFile.OpenStreamForWriteAsync()))
            {
                await writer.WriteLineAsync("new entry");
                await writer.WriteLineAsync(UserText.Text);
            }
        }

        private async void VerifyButton_Click(object sender, RoutedEventArgs e)
        {
            StorageFile openedFile = await ApplicationData.Current.LocalFolder.GetFileAsync("testfile3.txt");
            using (StreamReader reader = new StreamReader(await openedFile.OpenStreamForReadAsync()))
            {
                Results.Text = await reader.ReadToEndAsync();
            }
        }
    }
}

Imports System.IO
Imports Windows.Storage

NotInheritable Public Class BlankPage
    Inherits Page

    Private Async Sub CreateButton_Click(sender As Object, e As RoutedEventArgs)
        Dim newFile As StorageFile = Await ApplicationData.Current.LocalFolder.CreateFileAsync("testfile4.txt")

        Using writer As StreamWriter = New StreamWriter(Await newFile.OpenStreamForWriteAsync())
            Await writer.WriteLineAsync("new entry")
            Await writer.WriteLineAsync(UserText.Text)
        End Using
    End Sub

    Private Async Sub VerifyButton_Click(sender As Object, e As RoutedEventArgs)
        Dim openedFile As StorageFile = Await ApplicationData.Current.LocalFolder.GetFileAsync("testfile4.txt")
        Using reader As StreamReader = New StreamReader(Await openedFile.OpenStreamForReadAsync())
            Results.Text = Await reader.ReadToEndAsync()
        End Using
    End Sub
End Class

Contoh berikutnya menunjukkan kode XAML yang terkait dengan contoh sebelumnya.

<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">
        <TextBlock Text="Provide text to write to file:"></TextBlock>
        <TextBox Name="UserText" Width="400"></TextBox>
        <Button Name="CreateButton" Content="Create File" Click="CreateButton_Click"></Button>
        <Button Name="VerifyButton" Content="Verify Contents" Click="VerifyButton_Click"></Button>
        <TextBlock Name="Results"></TextBlock>
    </StackPanel>
</Page>

Keterangan

Catatan

Di Visual Basic dan C#, Anda dapat memanggil metode ini sebagai metode instans pada objek jenis IStorageFileapa pun . Saat Anda menggunakan sintaks metode instans untuk memanggil metode ini, hilangkan parameter pertama. Untuk informasi selengkapnya, lihat Metode Ekstensi (Visual Basic) atau Metode Ekstensi (Panduan Pemrograman C#).

Berlaku untuk

OpenStreamForWriteAsync(IStorageFolder, String, CreationCollisionOption)

Penting

API ini bukan kompatibel CLS.

Mengambil aliran untuk menulis ke file di folder induk yang ditentukan.

public:
[System::Runtime::CompilerServices::Extension]
 static System::Threading::Tasks::Task<System::IO::Stream ^> ^ OpenStreamForWriteAsync(Windows::Storage::IStorageFolder ^ rootDirectory, System::String ^ relativePath, Windows::Storage::CreationCollisionOption creationCollisionOption);
[System.CLSCompliant(false)]
public static System.Threading.Tasks.Task<System.IO.Stream> OpenStreamForWriteAsync (this Windows.Storage.IStorageFolder rootDirectory, string relativePath, Windows.Storage.CreationCollisionOption creationCollisionOption);
[<System.CLSCompliant(false)>]
static member OpenStreamForWriteAsync : Windows.Storage.IStorageFolder * string * Windows.Storage.CreationCollisionOption -> System.Threading.Tasks.Task<System.IO.Stream>
<Extension()>
Public Function OpenStreamForWriteAsync (rootDirectory As IStorageFolder, relativePath As String, creationCollisionOption As CreationCollisionOption) As Task(Of Stream)

Parameter

rootDirectory
IStorageFolder

Objek Windows Runtime IStorageFile yang berisi file untuk ditulis.

relativePath
String

Jalur, relatif terhadap folder akar, ke file yang akan ditulis.

creationCollisionOption
CreationCollisionOption

Nilai enumerasi Windows Runtime CreationCollisionOption yang menentukan perilaku yang akan digunakan ketika nama file yang akan dibuat sama dengan nama file yang ada.

Mengembalikan

Task<Stream>

Tugas yang mewakili operasi penulisan asinkron.

Atribut
CLSCompliantAttribute

Pengecualian

ArgumentNullException

rootDirectory atau relativePath adalah null.

ArgumentException

relativePath kosong atau hanya berisi karakter spasi kosong.

IOException

File tidak dapat dibuka atau diambil sebagai aliran.

Contoh

Contoh berikut menunjukkan cara membuka file sebagai Stream di aplikasi Bursa Windows, dan menulisnya dengan menggunakan instans StreamReader kelas .

using System;
using System.IO;
using Windows.Storage;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;

namespace ExampleApplication
{
    public sealed partial class BlankPage : Page
    {
        public BlankPage()
        {
            this.InitializeComponent();
        }

        private async void CreateButton_Click(object sender, RoutedEventArgs e)
        {
            using (StreamWriter writer =
                new StreamWriter(await ApplicationData.Current.LocalFolder.OpenStreamForWriteAsync(
                "testfile.txt",  CreationCollisionOption.OpenIfExists)))
            {
                await writer.WriteLineAsync("new entry");
                await writer.WriteLineAsync(UserText.Text);
            }
        }

        private async void VerifyButton_Click(object sender, RoutedEventArgs e)
        {
            StorageFile openedFile = await ApplicationData.Current.LocalFolder.GetFileAsync("testfile.txt");
            using (StreamReader reader = new StreamReader(await openedFile.OpenStreamForReadAsync()))
            {
                Results.Text = await reader.ReadToEndAsync();
            }
        }
    }
}

Imports System.IO
Imports Windows.Storage

NotInheritable Public Class BlankPage
    Inherits Page

    Private Async Sub CreateButton_Click(sender As Object, e As RoutedEventArgs)
        Using writer As StreamWriter =
               New StreamWriter(Await ApplicationData.Current.LocalFolder.OpenStreamForWriteAsync(
               "testfile.txt", CreationCollisionOption.OpenIfExists))
            Await writer.WriteLineAsync("new entry")
            Await writer.WriteLineAsync(UserText.Text)
        End Using
    End Sub

    Private Async Sub VerifyButton_Click(sender As Object, e As RoutedEventArgs)
        Dim openedFile As StorageFile = Await ApplicationData.Current.LocalFolder.GetFileAsync("testfile.txt")
        Using reader As StreamReader = New StreamReader(Await openedFile.OpenStreamForReadAsync())
            Results.Text = Await reader.ReadToEndAsync()
        End Using
    End Sub
End Class

Contoh berikutnya menunjukkan kode XAML yang terkait dengan contoh sebelumnya.

<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">
        <TextBlock Text="Provide text to write to file:"></TextBlock>
        <TextBox Name="UserText" Width="400"></TextBox>
        <Button Name="CreateButton" Content="Create File" Click="CreateButton_Click"></Button>
        <Button Name="VerifyButton" Content="Verify Contents" Click="VerifyButton_Click"></Button>
        <TextBlock Name="Results"></TextBlock>
    </StackPanel>
</Page>

Keterangan

Catatan

Di Visual Basic dan C#, Anda dapat memanggil metode ini sebagai metode instans pada objek jenis IStorageFolderapa pun . Saat Anda menggunakan sintaks metode instans untuk memanggil metode ini, hilangkan parameter pertama. Untuk informasi selengkapnya, lihat Metode Ekstensi (Visual Basic) atau Metode Ekstensi (Panduan Pemrograman C#).

Berlaku untuk