Hi,

I'm creating a little multithreaded FTP Client. I used to do this with the INET API functions. Now i want to try it with sockects in VB.NET. I can connect and execute some commands on the server but the LIST command or transfering files doesnt work.

I tryed different ways to find the solution for this.
Changing the Socket / Stream Options doesnt help.

Code:
Imports System.Net
Imports System.Net.Sockets

Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents Button2 As System.Windows.Forms.Button
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.Button1 = New System.Windows.Forms.Button()
        Me.TextBox1 = New System.Windows.Forms.TextBox()
        Me.Button2 = New System.Windows.Forms.Button()
        Me.SuspendLayout()
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(184, 168)
        Me.Button1.Name = "Button1"
        Me.Button1.TabIndex = 0
        Me.Button1.Text = "Button1"
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(208, 240)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.TabIndex = 1
        Me.TextBox1.Text = "TextBox1"
        '
        'Button2
        '
        Me.Button2.Location = New System.Drawing.Point(224, 272)
        Me.Button2.Name = "Button2"
        Me.Button2.TabIndex = 2
        Me.Button2.Text = "Button2"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(584, 437)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.Button2, Me.TextBox1, Me.Button1})
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private _FTPConn As Socket
    Private _BufferIn() As Byte

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim _EP As IPEndPoint = New IPEndPoint(IPAddress.Parse("127.0.0.1"), 21)
        _FTPConn = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
        _FTPConn.Connect(_EP)
        ReDim _BufferIn(1024)
        _FTPConn.BeginReceive(_BufferIn, 0, _BufferIn.Length, SocketFlags.None, AddressOf StreamIn, Nothing)

        System.Threading.Thread.CurrentThread().Sleep(1000)
        SendBuffer("USER anonymous")

        System.Threading.Thread.CurrentThread().Sleep(1000)
        SendBuffer("PASS [email protected]")

        System.Threading.Thread.CurrentThread().Sleep(1000)
        SendBuffer("SYST")

        System.Threading.Thread.CurrentThread().Sleep(1000)
        SendBuffer("PWD")

        System.Threading.Thread.CurrentThread().Sleep(1000)
        SendBuffer("TYPE A")

        System.Threading.Thread.CurrentThread().Sleep(1000)
        SendBuffer("PASV")

        System.Threading.Thread.CurrentThread().Sleep(1000)
        SendBuffer("LIST")

        'System.Threading.Thread.CurrentThread().Sleep(1000)
        'SendBuffer("DOWNLOAD")
    End Sub

    Private Sub StreamIn(ByVal ar As IAsyncResult)
        Try
            SyncLock _FTPConn
                _FTPConn.EndReceive(ar)
            End SyncLock

            Debug.Write(System.Text.Encoding.Default.GetString(_BufferIn))
            ReDim _BufferIn(1024)

            SyncLock _FTPConn
                _FTPConn.BeginReceive(_BufferIn, 0, _BufferIn.Length, SocketFlags.None, AddressOf StreamIn, Nothing)
            End SyncLock
        Catch ode As ObjectDisposedException
            Debug.Write(ode)
            Exit Sub
        Catch se As SocketException
            Debug.Write(se)
            Exit Sub
        Catch e As Exception
            Debug.Write(e)
            Exit Sub
        End Try
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        SendBuffer(TextBox1.Text)
    End Sub

    Private Sub SendBuffer(ByVal Buffer As String)
        Dim _BufferOut(1024) As Byte
        Debug.Write(Buffer & Chr(10))
        _BufferOut = System.Text.Encoding.Default.GetBytes(Buffer & Chr(10))
        _FTPConn.Send(_BufferOut, _BufferOut.Length, SocketFlags.None)
    End Sub
End Class