SeekOrigin SeekOrigin SeekOrigin SeekOrigin Enum

定義

指定資料流中要用於搜尋的位置。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
繼承
屬性

欄位

Begin Begin Begin Begin 0

指定資料流的開端。Specifies the beginning of a stream.

Current Current Current Current 1

指定資料流中的目前位置。Specifies the current position within a stream.

End End End End 2

指定資料流的末端。Specifies the end of a stream.

範例

下列範例示範如何在資料流,結尾回溯開始閱讀,以及如何從指定的點,資料流中讀取。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

備註

SeekOriginSeek方法StreamBufferedStreamFileStreamMemoryStreamBinaryWriter,和其他類別。SeekOrigin is used by the Seek methods of Stream, BufferedStream, FileStream, MemoryStream, BinaryWriter, and other classes. Seek方法會採用位移的參數所指定的位置相對SeekOriginThe Seek methods take an offset parameter that is relative to the position specified by SeekOrigin.

適用於

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