Using events in IE hosted windows form controls

Question

I've created a windows form control which works successfully hosted in Internet Explorer. I'd like to give it an event and be able to respond to the event through javascript. I found a link that talks about it here. It shows me how to create the interfaces but I'm not sure how to fire the event from my control?

Here's my code snippetS:

//Control Code:
public class CardReader : Panel,ICardReaderEvents, ICardReaderProperties
{
   public void Error()
   {
   }
   public void Success()
   {
   }
}

//Interface for events
[Guid("DD0C202B-12B4-4457-9FC6-05F88A6E8BC5")]
[InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
public interface ICardReaderEvents
{
    [DispId(0x60020000)]
    void Error();

    [DispId(0x60020001)]
    void Success();
}

//Interface for public properties/methods
public interface ICardReaderProperties
{
     ...
}

//JavaScript to handle events
<SCRIPT FOR="CardReader1" EVENT="Error">
    window.status = "Error...";
</SCRIPT>

<SCRIPT FOR="CardReader1" EVENT="Success">
    window.alert("Success");
    window.status = "";
</SCRIPT>

Answer 1

You are implementing it wrong in your CardReader class:

public event Error;
public event Success;

protected void OnError()
{
    if(Error != null)
        Error();
}

protected void OnSuccess()
{
    if(Success != null)
        Success();
}

If your ICardReaderEvents interface changes to have Error and Success take parameters, then just call them in OnError and OnSuccess.

Answer 2

So, now you need to know how to hook it in the Javascript? Here is how I know how to do it:

<object id="CR" ...></object>

<script type="text/javascript">
  function CR::Error()
  {
    alert("Error!");
  }

  function CR::Success()
  {
    alert("Success");
  }
</script>