Extending Generic Control

I would like to add properties to controls of every type. For example, each generic control has a "Tag" property. I'd like to add a property "ControlDescription" and some others to do some things that really will not help to explain.

I know how to create extended versions of each TYPE of control, one by one. I can do the button, the radioButton, the checkBox, etc. But that would be a lot of duplicitous coding, not to mention duplicitous upkeep.

On a one by one basis, you can do this:

CustomLabel myLabel=new CustomLabel();

But to extend all controls, you can't do this:

Label myLabel=new CustomControl() ** hoping that Label will inherit from Control since CustomControl() inherits from Control.

How can I do what I want?

Thanks.

Interesting question!

However, I'm not certain that there is a way to express that under the current standard. The "obvious" way to me would be to define a generic class like:

Code:

---

public class GenericDerived<T> : T
{
    //...Class implementation
}

---

But that will fail, because C# will not allow you to "generically" extend a class specified by a type parameter.

Possibly some strategy involving reflection...?

Anyone have any bright ideas?

I didn't think of Reflection, so thanks for the suggestion. I see nothing in PropertyInfo that allows the addition of a property to a particular type.

Where class CustomControl: Control....

Casting (Label)newCustomControl does not work.

Casting (CustomControl)newLabel does not work, either.

Here's my suggestion if it's what you're looking for

Code:

---

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        public Label l = new Label();

        private void Form1_Load(object sender, EventArgs e)
        {
           
            l.Text = "iuhiuhmihbmiuhb";
            this.Controls.Add(l); 
        }

        private void button1_Click(object sender, EventArgs e)
        {
            l.SetControlDescription("this is a description");
            l.Text = (string)l.GetControlDescription();
        }
    }
}

namespace System.Windows.Forms
{
    public static class ControlExtensions
    {
        private static object ControlDescription;
        public static object GetControlDescription(this Control control)
        {
            return ControlDescription;
        }
        public static void SetControlDescription(this Control control, object o)
        {
            ControlDescription = o;
        }
    }
}

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