Generic All Controls Method

Question

Couldn\'t think of a better title so appologies..

I\'m trying to convert this method, which will retrieve all child controls of a form, to be an extension method as

Answer 1

The problem is that Concat would want an IEnumerable<T> as well - not an IEnumerable<Control>. This should work though:

public static IEnumerable<T> GetAll<T>(this Control control) where T : class
{
    var controls = control.Controls.Cast<Control>();

    return controls.SelectMany(ctrl => GetAll<T>(ctrl))
                                .Concat(controls.OfType<T>()));
}