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FileStream.Position Property

Gets or sets the current position of this stream.

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

public override long Position { get; set; }

Property Value

Type: System.Int64
The current position of this stream.


The stream does not support seeking.


An I/O error occurred.

- or -

The position was set to a very large value beyond the end of the stream in Windows 98 or earlier.


Attempted to set the position to a negative value.


Attempted seeking past the end of a stream that does not support this.

Seeking to any location beyond the length of the stream is supported. When you seek beyond the length of the file, the file size grows. In Microsoft Windows NT and newer, any data added to the end of the file is set to zero. In Microsoft Windows 98 or earlier, any data added to the end of the file is not set to zero, which means that previously deleted data is visible to the stream. Setting the position of the stream to a large value beyond the end of the stream in Windows 98 or earlier may result in an exception being raised.

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

The following example uses the Length and Position properties to check for an end-of-file condition.

if( s.Length==s.Position )
   Console.WriteLine("End of file has been reached.");

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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