problem implementing a com component callback procedure

[sclement]

Hi

I am working with a com component, which I have added a reference to in my C#. I am using windows vista (32 bit) and VS2005.

I have to implement a callback object which handles data being returned from the com object, which derives from an interface called IDeviceEvents which is part of the com component, which I have attempted to do in my c# code:

unsafe class cFM2Notify : IDeviceEvents
{
    public string m_CallbackEvent = "";

    public void NotifyData(IFM2DeviceEvents CallbackData)
    {
    }

    public string CallbackEvent
    {
        get
        {
            return m_CallbackEvent = CallbackEvent;
        }

        set
        {
            CallbackEvent = m_CallbackEvent;
        }
    }
}

This is a shortened version - there are actually a few more properties and methods that I am required to implement, other than the ones shown.

The code builds ok, however, it falls over when run, a StackOverflowException being generated.

My VB.net colleague has suggested that I make the class com visible by prefixing the cFM2Notify declaration with[ComVisible(true)]. However I still a StackOverflowException being generated.

Any ideas on what I am doing wrong?

Cheers

Simon

[darwen]

You're not writing VB here you know : we have the 'return' keyword in C# for returning values from functions.

The problem lies in your CallbackEvent property - it should be :

    public string CallbackEvent
    {
        get
        {
            return m_CallbackEvent;
        }

        set
        {
            m_CallbackEvent = value;
        }
    }

If you've coded your other properties the same way then they will need changing too.

Darwen.

[sclement]

Hi Darwen

Thanks for the reply, it now works. Rather silly mistake on my part

thanks again

simon