StreamWriter.WriteAsync StreamWriter.WriteAsync StreamWriter.WriteAsync StreamWriter.WriteAsync Method

Definition

Writes data to the stream asynchronously.

Overloads

WriteAsync(Char[], Int32, Int32) WriteAsync(Char[], Int32, Int32) WriteAsync(Char[], Int32, Int32) WriteAsync(Char[], Int32, Int32)

Writes a subarray of characters to the stream asynchronously.

WriteAsync(ReadOnlyMemory<Char>, CancellationToken) WriteAsync(ReadOnlyMemory<Char>, CancellationToken)
WriteAsync(Char) WriteAsync(Char) WriteAsync(Char) WriteAsync(Char)

Writes a character to the stream asynchronously.

WriteAsync(String) WriteAsync(String) WriteAsync(String) WriteAsync(String)

Writes a string to the stream asynchronously.

WriteAsync(Char[], Int32, Int32) WriteAsync(Char[], Int32, Int32) WriteAsync(Char[], Int32, Int32) WriteAsync(Char[], Int32, Int32)

Writes a subarray of characters to the stream asynchronously.

public:
 override System::Threading::Tasks::Task ^ WriteAsync(cli::array <char> ^ buffer, int index, int count);
[System.Runtime.InteropServices.ComVisible(false)]
public override System.Threading.Tasks.Task WriteAsync (char[] buffer, int index, int count);
override this.WriteAsync : char[] * int * int -> System.Threading.Tasks.Task
Public Overrides Function WriteAsync (buffer As Char(), index As Integer, count As Integer) As Task

Parameters

buffer
Char[]

A character array that contains the data to write.

index
Int32 Int32 Int32 Int32

The character position in the buffer at which to begin reading data.

count
Int32 Int32 Int32 Int32

The maximum number of characters to write.

Returns

A task that represents the asynchronous write operation.

Exceptions

The index plus count is greater than the buffer length.

The stream writer is currently in use by a previous write operation.

Examples

The following example shows how to write multiple characters to a text file by using the WriteAsync(Char[], Int32, Int32) method.

using System;
using System.Text;
using System.IO;

namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            WriteCharacters();
        }

        static async void WriteCharacters()
        {
            UnicodeEncoding ue = new UnicodeEncoding();
            char[] charsToAdd = ue.GetChars(ue.GetBytes("Example string"));
            using (StreamWriter writer = File.CreateText("newfile.txt"))
            {
                await writer.WriteAsync(charsToAdd, 0, charsToAdd.Length);
            }
        }
    }
}
Imports System.IO
Imports System.Text

Module Module1

    Sub Main()
        WriteCharacters()
    End Sub

    Async Sub WriteCharacters()
        Dim ue As UnicodeEncoding = New UnicodeEncoding()
        Dim charsToAdd() = ue.GetChars(ue.GetBytes("Example string"))

        Using writer As StreamWriter = File.CreateText("newfile.txt")
            Await writer.WriteAsync(charsToAdd, 0, charsToAdd.Length)
        End Using
    End Sub
End Module

WriteAsync(ReadOnlyMemory<Char>, CancellationToken) WriteAsync(ReadOnlyMemory<Char>, CancellationToken)

public override System.Threading.Tasks.Task WriteAsync (ReadOnlyMemory<char> buffer, System.Threading.CancellationToken cancellationToken = null);
override this.WriteAsync : ReadOnlyMemory<char> * System.Threading.CancellationToken -> System.Threading.Tasks.Task

Parameters

Returns

WriteAsync(Char) WriteAsync(Char) WriteAsync(Char) WriteAsync(Char)

Writes a character to the stream asynchronously.

public:
 override System::Threading::Tasks::Task ^ WriteAsync(char value);
[System.Runtime.InteropServices.ComVisible(false)]
public override System.Threading.Tasks.Task WriteAsync (char value);
override this.WriteAsync : char -> System.Threading.Tasks.Task
Public Overrides Function WriteAsync (value As Char) As Task

Parameters

value
Char Char Char Char

The character to write to the stream.

Returns

A task that represents the asynchronous write operation.

Exceptions

The stream writer is currently in use by a previous write operation.

Examples

The following example shows how to write a single character (the letter "a") to a text file by using the WriteAsync(Char) method.

using System;
using System.IO;

namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            WriteCharacters();
        }

        static async void WriteCharacters()
        {
            using (StreamWriter writer = File.CreateText("newfile.txt"))
            {
                await writer.WriteAsync('a');
            }
        }
    }
}
Imports System.IO
Imports System.Text

Module Module1

    Sub Main()
        WriteCharacters()
    End Sub

    Async Sub WriteCharacters()
        Dim oneLetter As Char = "a"
        Using writer As StreamWriter = File.CreateText("newfile.txt")
            Await writer.WriteAsync(oneLetter)
        End Using
    End Sub
End Module

WriteAsync(String) WriteAsync(String) WriteAsync(String) WriteAsync(String)

Writes a string to the stream asynchronously.

public:
 override System::Threading::Tasks::Task ^ WriteAsync(System::String ^ value);
[System.Runtime.InteropServices.ComVisible(false)]
public override System.Threading.Tasks.Task WriteAsync (string value);
override this.WriteAsync : string -> System.Threading.Tasks.Task
Public Overrides Function WriteAsync (value As String) As Task

Parameters

value
String String String String

The string to write to the stream. If value is null, nothing is written.

Returns

A task that represents the asynchronous write operation.

Exceptions

The stream writer is currently in use by a previous write operation.

Examples

The following example shows how to write a string to a text file by using the WriteAsync(String) method.

using System;
using System.IO;

namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            WriteCharacters();
        }

        static async void WriteCharacters()
        {
            using (StreamWriter writer = File.CreateText("newfile.txt"))
            {
                await writer.WriteAsync("Example text as string");
            }
        }
    }
}
Imports System.IO
Imports System.Text

Module Module1

    Sub Main()
        WriteCharacters()
    End Sub

    Async Sub WriteCharacters()

        Using writer As StreamWriter = File.CreateText("newfile.txt")
            Await writer.WriteAsync("Example text as string")
        End Using
    End Sub
End Module

Applies to