Windows Dev Center

The topic you requested is included in another documentation set. For convenience, it's displayed below. Choose Switch to see the topic in its original location.

BinaryWriter.Write Method (Char)


Writes a Unicode character to the current stream and advances the current position of the stream in accordance with the Encoding used and the specific characters being written to the stream.

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

Public Overridable Sub Write (
	ch As Char


Type: System.Char

The non-surrogate, Unicode character to write.

Exception Condition

An I/O error occurs.


The stream is closed.


ch is a single surrogate character.

Because of data formatting conflicts, using this method with the following encodings is not recommended:

  • UTF-7

  • ISO-2022-JP


For a list of common I/O tasks, see Common I/O Tasks.

Unicode surrogate characters must be written out as pairs together in the same call, not individually. If you require support for surrogate pairs in your application, consider using a character array and the Write method overload.

The following code example shows how to read and write data using memory as a backing store.

Imports System
Imports System.IO

Public Class BinaryRW

    Shared Sub Main()

        Dim i As Integer = 0
        Dim invalidPathChars() As Char = Path.InvalidPathChars
        Dim memStream As new MemoryStream()
        Dim binWriter As New BinaryWriter(memStream)

        ' Write to memory.
        binWriter.Write("Invalid file path characters are: ")
        For i = 0 To invalidPathChars.Length - 1
        Next i

        ' Create the reader using the same MemoryStream 
        ' as used with the writer.
        Dim binReader As New BinaryReader(memStream)

        ' Set Position to the beginning of the stream.
        memStream.Position = 0

        ' Read the data from memory and write it to the console.
        Dim memoryData( _
            CInt(memStream.Length - memStream.Position) - 1) As Char
        For i = 0 To memoryData.Length - 1
            memoryData(i) = binReader.ReadChar()
        Next i

	End Sub
End Class

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
Return to top
© 2015 Microsoft