TextWriter.WriteAsync Method (Char(), Int32, Int32)

.NET Framework 4.6 and 4.5

Writes a subarray of characters to the text string or stream asynchronously.

Namespace:   System.IO
Assembly:  mscorlib (in mscorlib.dll)

<HostProtectionAttribute(SecurityAction.LinkDemand, ExternalThreading := True)>
Public Overridable Function WriteAsync (
	buffer As Char(),
	index As Integer,
	count As Integer
) As Task


Type: System.Char()

The character array to write data from.

Type: System.Int32

The character position in the buffer at which to start retrieving data.

Type: System.Int32

The number of characters to write.

Return Value

Type: System.Threading.Tasks.Task

A task that represents the asynchronous write operation.

Exception Condition

buffer is null.


The index plus count is greater than the buffer length.


index or count is negative.


The text writer is disposed.


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

The TextWriter class is an abstract class. Therefore, you do not instantiate it in your code. For an example of using the WriteAsync method, see the StreamWriter.WriteAsync method.

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 4.5
Portable Class Library
Supported in: portable .NET platforms
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1
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