How do I get EventTarget in an HttpModule's Begin Request

Question

I am writing some custom logging for our asp.net forms application, and I am able to get the request's url, but on post backs, I would like to get something like __EVENTTARGET to identify what control/button produced said postback.

I thought I could use the Request.Form["__EVENTTARGET"] but within the begin request event, this is set to an empty string on post back.

any idea's of how to get this information on postback? or do I have to wait until the end request to retrieve this information?

Answer 1

Ok, since this doesn't seem to be an interesting question for anyone,

I finally figured out why __EventTarget is not in the Request.Form[] dictionary. asp buttons do not use the _dopostback submittion. Rather, then do a standard form submittion, and send the button's ID in the Request.Form[] dictionary as a field.

lucky for our system, all buttons always start with "btn" so I could identify which button caused the submittion. here is the basic code I came up with:

 if (request.HttpMethod == "POST")
            {
                potentialTarget = request.Form["__EVENTTARGET"];
                if (string.IsNullOrWhiteSpace(potentialTarget))
                {
                    foreach (string ctrlName in request.Form)
                    {
                        if (!ctrlName.ToLower().Contains("$btn")) 
                            continue;
                        potentialTarget = ctrlName;
                        break;
                    }
                }
            }