Question

Is it possible to add a serial port control to a web application. I’ve tried creating one programmatically, but i have issues with the port staying open. I’m not sure how to fix that except by adding a serial port control somehow to the web page. Any ideas on how I can accomplish this task? Thanks in advance.

the following is the code I currently have:

public partial class LoadCellTest : System.Web.UI.Page
{ 
SerialPort serialPort1 = new SerialPort("COM3",9600,Parity.None,8,StopBits.One);

 protected void Page_Load(object sender, EventArgs e)
{

    serialPort1.DataReceived += new SerialDataReceivedEventHandler(serialPort1_DataReceived);
    serialPort1.ErrorReceived += new SerialErrorReceivedEventHandler(serialPort1_ErrorReceived);

}

delegate void SerialDataReceivedDelegate(object sender, SerialDataReceivedEventArgs e);
delegate void SerialErrorReceivedDelegate(object sender, SerialErrorReceivedEventArgs e);


protected void serialPort1_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
   TextBox1.Text = (serialPort1.ReadExisting());
   if (serialPort1.ReadExisting().Length == 0)
   {
       ListBox1.Items.Insert(0, TextBox1.Text);
       TextBox1.Text = "";
   }
}
protected void button1_Click(object sender, EventArgs e)
{
    try
    {
        if (serialPort1.IsOpen)
        {
            serialPort1.Close();
            button1.Text = "Start";
        }
        else
        {
            serialPort1.Open();
            button1.Text = "Stop";
        }
    }
    catch (IOException ex)
    {
        MessageBox.Show(ex.Message);
    }
}

Answer 1

Turning my comments into an answer…

The serial port code is server-side code. You can’t do it on the client with ASP.NET.

Creating an ActiveX or other fat client control is a load of work, and just not a good idea.

My recommendation would be to continue on with your WinForms app for the code where you need the scanner, and add a menu to it to enable you to launch a separate ASP.NET web app for the reports/data access.

If you want to make it more “seamless” for the users, you can add a form with a WebBrowser control that loads your report/data access site. To them it will just be a “part of the application”.

THAT SAID, depending on the device you have connected to the port, there may be an even simpler option.

One of our barcode scanners comes with software that just takes barcode data as it’s scanned and pastes it into whatever open document has focus. If you’re working in Notepad, the scanned data is pasted into Notepad. If you have a web app open, and the cursor in a text box, the data simply pastes in there.

It’s a simpler option to implement, BUT it’s harder on the users, because if they’re not technical, they’re going to call you wondering why the barcode beeps but doesn’t populate the text box. (The answer will be “Because your cursor isn’t in the text box or the form doesn’t have focus”)

So I go back to recommendation #1.