Question

First I have a Listbox and set the DataSource to a MyObjectCollection

MyObjectCollection implements the Interface IListSource wich contains MyObject’s

MyObject has the method

public override string ToString()
{
    return "test";
}

The Listbox now displays “test” for each element in the MyObjectCollection.

But if I apply the IListSource interface to MyObject, too. The Listbox shows an empty string. How to fix that in the “MyObject” class.
A workaround is to fix it in the Listbox Format event, but than every GUI element has to implement this workaround :/

Answer 1

Generally, things should either be lists, or should be an entity for binding. If it is a list (IList or IListSource) then much of the data-binding API will assume you actually want (for simple-binding scenarios, i.e. one row) the first item from the sublist.

I would simply change it so that MyObject doesn’t implement IListSource, but encapsulates it, perhaps exposing it via a Items property. You could also look at whether a custom TypeConverter would work (I’ll investigate…)