[RESOLVED] HELP with MultiThreading

[dr_aybyd]

Hi, I am new in vb.Net

It is my previous problem in vb6, its hard to multithread using vb6 so I migrate my codes to vb.Net.

How can I multithread this two loops so that this process is running at the same time.
Because when I start my second Loop, my first loop stop in executing. It will start again when my 2nd loop finished.

Here is my 2 Loops:

Dim Ret As Integer
        Dim i As Short
        For i = 0 To ListBox1.Items.Count - 1
            System.Windows.Forms.Application.DoEvents()
            ListBox1.SelectedIndex = i
            ListBox1.Refresh()

            WriteToLog("Sending SMS to ->  " & txtDestination.Text, System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Yellow))

            Ret = Device.SendSMS(txtDestination.Text, txtmsg.Text)
            Device.GetLastError(0)
            If Ret > 1 Then
                WriteToLog("SMS Sent to ->  " & txtDestination.Text, System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Lime))
            End If
            If Ret = -22 Then
                WriteToLog("ERROR Sending to ->  " & txtDestination.Text, System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red))
                WriteToLog("ERROR: PDU error, Signal, Check Account balance.", System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red))
            End If
            If Ret = -20 Then
                WriteToLog("ERROR Sending to ->  " & txtDestination.Text, System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red))
                WriteToLog("ERROR: SMS Service, Check Account balance.", System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red))
            End If
            If Ret = -19 Then
                WriteToLog("ERROR Sending to ->  " & txtDestination.Text, System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red))
                WriteToLog("ERROR: SMSC NOT FOUND.", System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red))
            End If
            If Ret = -2 Then
                WriteToLog("ERROR Sending to ->  " & txtDestination.Text, System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red))
                WriteToLog("ERROR: PORT FAIL.", System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red))
            End If
        Next

Dim Ret2 As Integer
        Dim j As Short
        For j = 0 To ListBox2.Items.Count - 1
            System.Windows.Forms.Application.DoEvents()
            ListBox2.SelectedIndex = j
            ListBox2.Refresh()

            WriteToLog2("Sending SMS to ->  " & txtDestination2.Text, System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Yellow))

            Ret2 = Device2.SendSMS(txtDestination2.Text, txtmsg.Text)
            Device2.GetLastError(0)
            If Ret2 > 1 Then
                WriteToLog2("SMS Sent to ->  " & txtDestination2.Text, System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Lime))
            End If
            If Ret2 = -22 Then
                WriteToLog2("ERROR Sending to ->  " & txtDestination2.Text, System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red))
                WriteToLog2("ERROR: PDU error, Signal, Check Account balance.", System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red))
            End If
            If Ret2 = -20 Then
                WriteToLog2("ERROR Sending to ->  " & txtDestination2.Text, System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red))
                WriteToLog2("ERROR: SMS Service, Check Account balance.", System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red))
            End If
            If Ret2 = -19 Then
                WriteToLog2("ERROR Sending to ->  " & txtDestination2.Text, System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red))
                WriteToLog2("ERROR: SMSC NOT FOUND.", System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red))
            End If
            If Ret2 = -2 Then
                WriteToLog2("ERROR Sending to ->  " & txtDestination2.Text, System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red))
                WriteToLog2("ERROR: PORT FAIL.", System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red))
            End If
        Next

I have 2 connected GSM Modem in usb port.
That codes will send SMS in all contacts in my ListBox.