.NET การใช้งานระหว่าง Windows App กับเครื่อง Porttable Printer ซึ่งเครื่องนี้ต้องสั่งการผ่านระบบ Bluetooth

Private Sub btnConnect_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnConnect.Click

    '--close the serail port if it is open --
    If serialPort1.IsOpen Then
        serialPort1.Close()
    End If

    Try
        '-- configure the various parameters of the serial port --
        With serialPort1 
            .PortName = "COM22"
            .BaudRate = 9600
            .Parity = IO.Ports.Parity.None
            .StopBits = IO.Ports.StopBits.One
            .DataBits = 8
        End With

        ' -- now open the port
            serialPort1.Open()

        ' -- update the status if you like and 
        ' -- enable/disable the buttons --
          btnConnect.Enabled = False
          btnDisconnect.Enabled = True
     Catch ex As Exception
        MsgBox(ex.ToString())
     End Try                  
End Sub

private void btnConnect_Click(System.Object sender, System.EventArgs e)
{
	//--close the serail port if it is open --
	if (serialPort1.IsOpen) {
		serialPort1.Close();
	}

	try {
		//-- configure the various parameters of the serial port --
		var _with1 = serialPort1;
		_with1.PortName = "COM22";
		_with1.BaudRate = 9600;
		_with1.Parity = System.IO.Ports.Parity.None;
		_with1.StopBits = System.IO.Ports.StopBits.One;
		_with1.DataBits = 8;

		// -- now open the port
		serialPort1.Open();

		// -- update the status if you like and 
		// -- enable/disable the buttons --
		btnConnect.Enabled = false;
		btnDisconnect.Enabled = true;
	} catch (Exception ex) {
		Interaction.MsgBox(ex.ToString());
	}
}