SeekOrigin SeekOrigin SeekOrigin SeekOrigin Enum

定义

指定流中的位置以供查找使用。Specifies the position in a stream to use for seeking.

public enum class SeekOrigin
[System.Runtime.InteropServices.ComVisible(true)]
[System.Serializable]
public enum SeekOrigin
type SeekOrigin = 
Public Enum SeekOrigin
继承
属性

字段

Begin Begin Begin Begin 0

指定流的开始位置。Specifies the beginning of a stream.

Current Current Current Current 1

指定流中的当前位置。Specifies the current position within a stream.

End End End End 2

指定流的结束位置。Specifies the end of a stream.

示例

下面的示例演示如何读取向后开始流的结尾以及如何读取从流中的指定点。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.

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
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

注解

SeekOrigin 可供Seek的方法StreamBufferedStreamFileStreamMemoryStreamBinaryWriter,以及其他类。SeekOrigin is used by the Seek methods of Stream, BufferedStream, FileStream, MemoryStream, BinaryWriter, and other classes. Seek方法采用相对于指定的位置的偏移量的参数SeekOriginThe Seek methods take an offset parameter that is relative to the position specified by SeekOrigin.

适用于

另请参阅