Subclassed Textbox readonly font not recognized on form

Question

Building my baseclasses for user interface controls is getting there. I have command buttons derived with custom font assignment and put on a form, all is fine... However, identical code for the read-only property Font of a textbox is NOT recognized properly on the same form. It is ONLY taking the setting of the FORM and disregarding its own Font declaration.

public class MyTextbox : TextBox
{
    [ReadOnly(true)]
    public override Font Font
    { get { return new 
             Font( "Courier New", 12f, FontStyle.Regular, GraphicsUnit.Point ); 
          } 
    }
}

Answer 1

The Font property is an ambient property. If it was never assigned, it automatically matches the Font property of the container control. You never assigned it.

Do it like this:

public class MyTextbox : TextBox {
    Font mFont;
    public MyTextbox() {
        base.Font = mFont = new Font("Courier New", 12f, FontStyle.Regular, GraphicsUnit.Point);
    }

    [ReadOnly(true)]
    public override Font Font {
        get { return mFont; }
    }
}

Answer 2

With a help from "nobugz" (Thanks), I found this same failure when doing a ComboBox too. My result was the following...

My getter

get { return new Font( ... ); }

However, in nobugz response, something wasn't working quite right with the compiler, so in the constructor of the class

clas MyTextbox...
{
   public MyTextbox()
   {
      // it defaults itself from its own read-only font "new" object instance and works
      base.Font = Font;
   }
}