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FileStream.CanRead Property

Gets a value indicating whether the current stream supports reading.

[Visual Basic]
Overrides Public ReadOnly Property CanRead As Boolean
[C#]
public override bool CanRead {get;}
[C++]
public: __property bool get_CanRead();
[JScript]
public override function get CanRead() : Boolean;

Property Value

true if the stream supports reading; false if the stream is closed or was opened with write-only access.

Remarks

If a class derived from Stream does not support reading, calls to the Read, ReadByte, and BeginRead methods throw a NotSupportedException.

If the stream is closed, this property returns false.

Example

The following example demonstrates a use of the CanRead property. The output of this code is "MyFile.txt is not 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.

[Visual Basic] 
Imports System
Imports System.IO

Class TestRW

    Public Shared Sub Main()
        Dim fs As New FileStream("MyFile.txt", FileMode.OpenOrCreate, FileAccess.Read)
        If fs.CanRead And fs.CanWrite Then
            Console.WriteLine("MyFile.txt can be both written to and read from.")
        Else
            If fs.CanRead Then
                Console.WriteLine("MyFile.txt is not writable.")
            End If
        End If
    End Sub
End Class

[C#] 
using System;
using System.IO;
 
class TestRW 
{
    public static void Main(String[] args)
    {
        FileStream fs = new FileStream("MyFile.txt", FileMode.OpenOrCreate, FileAccess.Read);
        if (fs.CanRead && fs.CanWrite)
        {
            Console.WriteLine("MyFile.txt can be both written to and read from.");
        }
        else if (fs.CanRead)
        {
            Console.WriteLine("MyFile.txt is not writable.");
        }
    }
}

[C++] 
#using <mscorlib.dll>

using namespace System;
using namespace System::IO;

int main(void)
{
    FileStream * fs = new FileStream(S"MyFile.txt", FileMode::OpenOrCreate, FileAccess::Read);
    if ( fs->CanRead && fs->CanWrite )
    {
        Console::WriteLine(S"MyFile.txt can be both written to and read from.");
    } else {
        Console::WriteLine(S"MyFile.txt is not writable");
    }
    return 0;
}

[JScript] 
import System;
import System.IO;

class TestRW 
{
  public static function Main() : void 
  {

        var fs : FileStream = new FileStream("MyFile.txt", FileMode.OpenOrCreate, FileAccess.Read);
        if (fs.CanRead && fs.CanWrite)
        {
           Console.WriteLine("MyFile.txt can be both written to and read from.");
        }
        else if (fs.CanRead)
        {
           Console.WriteLine("MyFile.txt is not writable.");
     }
  }
}
TestRW.Main();

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework, Common Language Infrastructure (CLI) Standard

See Also

FileStream Class | FileStream Members | System.IO Namespace | Working with I/O | Reading Text from a File | Writing Text to a File

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