Question

Suppose I want to develop a custom, purely graphical control to be used in both WinForms as well as ASP.NET. The control will, based on some property settings and associated rules, render an image.

Obviously, I could just duplicate the code from the WinForms version to the ASP.NET version, but that would mean that if an error is found, or a rule is changed, I have two versions to update.

I could write a core class, with the various properties and rules needed, and the WinForms and ASP.NET control classes will have a property pointing to this core class, something like:

public class MyControlCore
{
    // all properties and control rules

    public void PaintTo(Graphics graphics)
    {
        // rendering of control
    }
}

public class MyWinFormsControl: Control
{
    public MyWinFormsControl(Control parent): base(parent)
    {
        CoreControl = new MyControlCore();
    }

    public MyControlCore CoreControl { get; private set; }

    protected override OnPaint(object sender, PaintEventArgs e)
    {
        CoreControl.PaintTo(e.Graphics);
    }
}

This will work, but in the property grid I would get a property CoreControl, containing the customization properties. Is there a way to have the property grid show the MyControlCore properties, instead of the CoreControl property with the sub properties?

I was thinking that I could perhaps accomplish this with TypeDescriptionProvider and related classes, but I’m unsure how to proceed and if it would even give me the results I’m after. I realize this would only help me in the designer, but that’s fine.

Answer 1

There is another choice. You could use partial classes and put the common code in a single file that you can link to from both projects.