' 导入命名空间
Imports System.IO
Imports System.Text

Class FStream

    Shared Sub Main()

        Const fileName As String = "Test#@@#.dat"

        ' Create random data to write to the file.
        Dim dataArray(100000) As Byte
        Dim randomGenerator As New Random()
        randomGenerator.NextBytes(dataArray)

        Dim fileStream As FileStream = _
            new FileStream(fileName, FileMode.Create)
        Try

            ' Write the data to the file, byte by byte.
            For i As Integer = 0 To dataArray.Length - 1
                fileStream.WriteByte(dataArray(i))
            Next i

            ' Set the stream position to the beginning of the stream.
            fileStream.Seek(0, SeekOrigin.Begin)

            ' Read and verify the data.
            For i As Integer = 0 To _
                CType(fileStream.Length, Integer) - 1

                If dataArray(i) <> fileStream.ReadByte() Then
                    Console.WriteLine("Error writing data.")
                    Return
                End If
            Next i
            Console.WriteLine("The data was written to {0} " & _
                "and verified.", fileStream.Name)
        Finally
            fileStream.Close()
        End Try
    
    End Sub
End Class

' 导入命名空间
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

' 导入命名空间
Imports System.IO

Module Module1

    Sub Main()
        Dim FileSt As FileStream = New FileStream("test.dat", FileMode.Create, FileAccess.Write, FileShare.Write)

        Try
            FileSt.Lock(0, 100)
            Console.WriteLine("Locked")
        Catch Ex As Exception
            Console.WriteLine(Ex.Message)
        End Try

        Try
            FileSt.Unlock(0, 100)
            Console.WriteLine("Unlocked")
        Catch Ex As Exception
            Console.WriteLine(Ex.Message)
        End Try

        Dim Values As Byte()
        Values = New Byte() {1, 2, 3, 4, 5}

        Try
            FileSt.Seek(0, SeekOrigin.Begin)
            FileSt.Write(Values, 0, 5)
            Console.WriteLine("Successfully updated file")
        Catch Ex As Exception
            Console.WriteLine(Ex.Message)
        End Try

    End Sub

End Module