SeekOrigin 列舉

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
SeekOrigin
屬性

欄位

Begin 0

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

Current 1

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

End 2

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

範例

下列範例顯示如何從資料流程結尾處開始讀取, 以及如何從資料流程中的指定點讀取。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.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

SeekOriginStream適用于BufferedStream、、 SeekFileStream、和其他類別的方法BinaryWriterMemoryStreamSeekOrigin is used by the Seek methods of Stream, BufferedStream, FileStream, MemoryStream, BinaryWriter, and other classes. 方法會採用相對於所SeekOrigin指定位置的 offset 參數。 SeekThe Seek methods take an offset parameter that is relative to the position specified by SeekOrigin.

適用於

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