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.NET Framework Class Library
SeekOrigin Enumeration

Specifies the position in a stream to use for seeking.

Namespace:   System.IO
Assemblies:   System.IO (in System.IO.dll)
  mscorlib (in mscorlib.dll)
Syntax
Public Enumeration SeekOrigin
public enum SeekOrigin
public enum class SeekOrigin
type SeekOrigin
public enum SeekOrigin
Members
Member nameDescription
Supported by the XNA Framework Supported by Portable Class LibraryBeginSpecifies the beginning of a stream.
Supported by the XNA Framework Supported by Portable Class LibraryCurrentSpecifies the current position within a stream.
Supported by the XNA Framework Supported by Portable Class LibraryEndSpecifies the end of a stream.
Remarks

SeekOrigin is used by the Seek methods of Stream, BufferedStream, FileStream, MemoryStream, BinaryWriter, and other classes. The Seek methods take an offset parameter that is relative to the position specified by SeekOrigin.

Examples

The following example shows how to read backwards starting at the end of the stream, and how to read from a specified point in the stream.

Imports System
Imports System.IO

Public Class FSSeek
    Public Shared Sub Main()
        Dim offset As Long 
        Dim nextByte As Integer 

        ' alphabet.txt contains "abcdefghijklmnopqrstuvwxyz" 
        Using fs As New FileStream("c:\temp\alphabet.txt", FileMode.Open, FileAccess.Read)

            For offset = 1 To fs.Length
                fs.Seek(-offset, SeekOrigin.End)
                Console.Write(Convert.ToChar(fs.ReadByte()))
            Next offset
            Console.WriteLine()

            fs.Seek(20, SeekOrigin.Begin)

            nextByte = fs.ReadByte()
            While (nextByte > 0)
                Console.Write(Convert.ToChar(nextByte))
                nextByte = fs.ReadByte()
            End While
            Console.WriteLine()

        End Using 
    End Sub 
End Class 

' This code example displays the following output: 
' 
' zyxwvutsrqponmlkjihgfedcba 
' uvwxyz
using System;
using System.IO;

public class FSSeek
{
    public static void Main()
    {
        long offset;
        int nextByte;

        // alphabet.txt contains "abcdefghijklmnopqrstuvwxyz" 
        using (FileStream fs = new FileStream(@"c:\temp\alphabet.txt", FileMode.Open, FileAccess.Read))
        {
            for (offset = 1; offset <= fs.Length; offset++)
            {
                fs.Seek(-offset, SeekOrigin.End);
                Console.Write(Convert.ToChar(fs.ReadByte()));
            }
            Console.WriteLine();

            fs.Seek(20, SeekOrigin.Begin);

            while ((nextByte = fs.ReadByte()) > 0)
            {
                Console.Write(Convert.ToChar(nextByte));
            }
            Console.WriteLine();
        }
    }
}
// This code example displays the following output: 
// 
// zyxwvutsrqponmlkjihgfedcba 
// uvwxyz
Version Information

.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

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Portable Class Library

Supported in: Portable Class Library