Imports System.Net
Public Class MainForm
    Dim ftpFilePath As String = Nothing

    Private Sub MainForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Control.CheckForIllegalCrossThreadCalls = False
    End Sub

    Private Sub btnBrowse_Click(sender As Object, e As EventArgs) Handles btnBrowse.Click
        Dim newFile As New OpenFileDialog
        If newFile.ShowDialog = Windows.Forms.DialogResult.OK Then
            txtFilePath.Text = newFile.FileName
            ftpFilePath = txtFTPServer.Text & "/" & IO.Path.GetFileName(txtFilePath.Text)
        End If
    End Sub

    Private Sub btnUpload_Click(sender As Object, e As EventArgs) Handles btnUpload.Click
        bWorker.RunWorkerAsync()
    End Sub

    Private Sub bWorker_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles bWorker.DoWork
        Dim request As FtpWebRequest = DirectCast(WebRequest.Create(New Uri(ftpFilePath)), FtpWebRequest)
        request.Method = WebRequestMethods.Ftp.UploadFile
        request.Credentials = New NetworkCredential(txtFTPUsername.Text, FTPPassword.Text)
        request.UseBinary = True
        request.UsePassive = False
        Dim fileStream() As Byte = System.IO.File.ReadAllBytes(txtFilePath.Text)
        Dim requestStream As System.IO.Stream = request.GetRequestStream()
        For offset As Integer = 0 To fileStream.Length Step 1024
            bWorker.ReportProgress(CType(offset * pBar.Maximum / fileStream.Length, Integer))
            Dim chSize As Integer = fileStream.Length - offset
            If chSize > 1024 Then chSize = 1024
            requestStream.Write(fileStream, offset, chSize)
        Next
        requestStream.Close()
        requestStream.Dispose()
    End Sub

    Private Sub bWorker_ProgressChanged(sender As Object, e As System.ComponentModel.ProgressChangedEventArgs) Handles bWorker.ProgressChanged
        pBar.Value = e.ProgressPercentage
        lblPercent.Text = e.ProgressPercentage & " %"
    End Sub

    Private Sub bWorker_RunWorkerCompleted(sender As Object, e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles bWorker.RunWorkerCompleted
        MsgBox("Finish uploading!")
    End Sub

End Class