Stream.CanWrite Property

When overridden in a derived class, gets a value indicating whether the current stream supports writing.

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

'Declaration
Public MustOverride ReadOnly Property CanWrite As Boolean

Property Value

Type: System.Boolean
true if the stream supports writing; otherwise, false.

If a class derived from Stream does not support writing, a call to Write, BeginWrite, or WriteByte throws a NotSupportedException.

If the stream is closed, this property returns false.

The following is an example of using the CanWrite property.

Imports System
Imports System.IO

Class TestRW    

    Public Shared Sub Main()
        Dim fs As New FileStream("MyFile.txt", FileMode.OpenOrCreate, _
           FileAccess.Write)
        If fs.CanRead And fs.CanWrite Then
            Console.WriteLine("MyFile.txt can be both written to and read from.")
        Else 
            If fs.CanWrite Then
                Console.WriteLine("MyFile.txt is writable.")
            End If 
        End If 
    End Sub 
End Class 

'This code outputs "MyFile.txt is writable." 
'To get the output message "MyFile.txt can be both written to and read from.", 
'change the FileAccess parameter to ReadWrite in the FileStream constructor.

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8
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