Visual Basic

Public Function GetPlatformList() As List(Of String)

    Dim result As New List(Of String)
    Dim dbCon As New OleDb.OleDbConnection(dbConnectionString)

    Dim dbCMD As OleDb.OleDbCommand
    Dim dbReader As OleDb.OleDbDataReader

    dbCMD = New OleDb.OleDbCommand("SELECT PlatformName FROM Platforms", dbCon)

    Try
        dbCon.Open()

        dbReader = dbCMD.ExecuteReader()
        Dim HasResult As Boolean = True
        Do Until Not HasResult
            Do While dbReader.Read()
                result.Add(dbReader.GetString(0))
            Loop
            HasResult = dbReader.NextResult()
        Loop

    Catch ex As Exception
        'Error Trying
        MsgBox("Error Accessing Database: " & ex.Message, MsgBoxStyle.Critical, "Database Error")
    End Try

    dbReader.Close()
    dbCon.Close()

    'Return the list of platforms
    Return result
End Function

Variable 'dbReader' is used before it has been assigned a value. A null reference exception could result at runtime.

Private Sub btnDL_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDL.Click

        btnDL.Enabled = True
        btnRef.Enabled = True
        btnULAbort.Enabled = True
        
        Try
            Disconnect()
        Catch ex As Exception

        End Try

        Dim Message As String = "[RequestFileDownload]"
        'SelectedItems(0) so that it knows to get the item from column 0 which is name
        Message += ListView1.SelectedItems(0).Text

        Dim filename As String

        If ListView1.SelectedItems.Count < 1 Or ListView1.SelectedItems.Count > 1 Then
            MsgBox("Please select a file")
            Exit Sub

        Else

            client = New TcpClient
            client.Connect("152.226.152.179", portNo)

            btnDL.Enabled = False
            SendMessage(Message)

            client.GetStream.BeginRead(msgData, 0, CInt(client.ReceiveBufferSize), AddressOf RReceiveMessage, Nothing)
            'MsgBox(FileRequest)
            If FileRequest = "[DLTotalBytes]" Then
                Dim DLTotal As String
                DLTotal = FileRequest.Remove(0, 14)
                FTP_Send(filename, "152.226.152.179")
            End If

            FTP_Receive(filename)

        End If

    End Sub

    Public Sub FTP_Receive(ByVal filename As String)

        Try
            '---get the local IP address
            Dim localAdd As System.Net.IPAddress = System.Net.IPAddress.Parse(ips.AddressList(0).ToString)


            Dim nws As NetworkStream = client.GetStream

            '---delete the file if it exists
            If File.Exists("C:\Documents and Settings\user\My Documents\My Received Files" & filename) Then
                File.Delete("C:\Documents and Settings\user\My Documents\My Received Files" & filename)
            End If

            '---create the file
            fs = New System.IO.FileStream("C:\Documents and Settings\user\My Documents\My Received Files" & filename, FileMode.Append, FileAccess.Write)

            Dim counter As Integer = 0
            Dim totalBytes As Integer = 0
            Do
                '---read the incoming data
                Dim bytesRead As Integer = nws.Read(msgData, 0, client.ReceiveBufferSize)
                totalBytes += bytesRead
                fs.Write(msgData, 0, bytesRead)

                '--update the status label
                ToolStripStatusLabel1.Text = "Downloading " & totalBytes & " bytes...."
                Application.DoEvents()
                System.Threading.Thread.Sleep(200)
                counter += 1

            Loop Until Not nws.DataAvailable
            ToolStripStatusLabel1.Text = "Downloading " & totalBytes & " bytes....Done."
            fs.Close()
            client.Close()

        Catch x As Exception

        End Try

    End Sub