Visual Studio - new "default" property values for inherited controls

Question

I'm looking for help setting a new default property value for an inherited control in Visual Studio:

class NewCombo : System.Windows.Forms.ComboBox
{
  public NewCombo() { DropDownItems = 50; }
}

The problem is that the base class property "DropDownItems" has a 'default' attribute set on it that is a different value (not 50). As a result, when I drag the control onto a form, the designer file gets an explicit 'mycontrol.DropDownItems = 50;' line.

At first this doesn't matter. But if later I change my inherited class to 'DropDownItems = 45;' in the constructor this does not affect any of the controls on any form since all those designer files still have the value 50 hardcoded in them. And the whole point was to have the value set in one place so I can deal with the customer changing his mind.

Obviously, if I were creating my own custom property in the subclass, I could give it its own designer default attribute of whatever I wanted. But here I'm wanting to change the default values of properties in the base. Is there any way to apply Visual Studio attributes to a base class member? Or is there some other workaround to get the result I want?

Thanks for any help

Answer 1

In your derived class you need to either override (or shadow using new) the property in question and then re-apply the default value attribute.

Answer 2

Well that was simple...guess it doesn't make a difference that the base member isn't virtual/overridable.

Answer 3

Just came across this too and the solution above does work, but... only in Designer it seems. I inherit from DataGridView, and want to eg. change the default border style to None. Override doesn't work ("cannot override inherited member System.Windows.Forms.DataGridView.BorderStyle.get' because it is not marked virtual, abstract, or override"), and the code below does not produce the desired result.

[DefaultValue(typeof(BorderStyle), "None")]
public override BorderStyle BorderStyle { get; set; }

Any ideas how to remedy the problem? Perhaps I'm doing something very wrong?