Question

I am supposed to create a custom ComboBox by deriving a class from ComboBox in my WinForms application. I have never done this before and not able to find many good example from Google.

I am required to derive a custom combobox so that I can make the custom combobox type-bound to a particular object.

This is what I have so far.

CustomComboBox.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace MAPClient {
    class MAPCodeComboBox : ComboBox {

    }
}

I have some specific questions:

1. Which methods do I need to override?
2. How do I use it in my VS2010 designer mode?

Answer 1

Okay, finally I have the following for a custom type-bounded ComboBox. Let me know if I am doing something wrong.

MAPComboBox.cs

using System.Collections.Generic;
using System.Windows.Forms;

namespace MAPClient {
    class MAPComboBox : ComboBox {
        private MAPCodeObjectCollection MAPCodeItemCollection = null;

        new public MAPCodeObjectCollection Items {
            // override
        }

        new public List<MAPCode> DataSource {
            // override
        }

        public MAPCodeComboBox() { }
    }
}

MAPCodeObjectCollection.cs

using System.Windows.Forms;

namespace MAPClient {
    class MAPCodeObjectCollection : ComboBox.ObjectCollection {
        public MAPCodeObjectCollection(ComboBox owner) : base(owner) { }

        new public int Add(object item) {
            // override
        }

        new public void Insert(int index, object item) {
            // override
        }
    }
}