Custom SelectedValue attribute

Question

I am creating a completely custom (only inherits from WebControl) combobox/dropdownlist search control with autoComplete capabilities.

JQuery handles assigning the onhover and onclick events for list items (divs with strings in them) and handles the web service call for getting the list of items for the matching text.

The server handles the custom attributes and control rendering.

The issue is that I need to implement a property that is similar to SelectedValue so that when a user selects an item from the search results, the value can be used on the server for other processing. I have done days of research but have not found a clear, concise way of handling the post back data.

I did read a blog that mentioned implementing the IPostBackDataHandler interface, but the implementation of RaisePostDataChangeEvent() calls for calling a server method (like SelectedIndexChange) that I am not implementing at the moment.

public void RaisePostDataChangedEvent()
{
    this.SelectedIndexChanged(EventArgs.Empty);
}

Now for the question: Does anyone have advice for handling this? Or am I better off simply inheriting from the dropdownlist control and overriding the existing functionality?

I feel like I'm missing a very small piece that will fit this all together.

Answer 1

Have you considered pulling down the source code from Microsoft's source server and taking a look at how they implemented DropDownList? This would allow you so see how they solved the binding and events part of the problem and give you a good idea what it does otherwise. This way you can decide if you want to inherit from it, or if you can just borrow some ideas for how they implemented IPostBackDataHandler.

Since I have no idea what specifically you are doing, I couldn't advise you if you should inherit from dropdown as it is, but based on my impressions of what you are doing I'd say you probably don't.

Also you might look at source from the AjaxControlToolkit as it has a similar component. Again, you can get ideas for how these specific things are handled and adapt them to your own needs.