Now let's get started on the actual code… First up is the base class all your skinned controls will derive from; the abstract class SkinControl.

using System;
using System.Web.UI;
namespace MySite.Controls
{
    public abstract class SkinControl : Control, INamingContainer
    {
        // ***********
        //  VARIABLES
        // ***********
        private Control skinControl    = null;
        private    string  skinVirtualPath = null;
        // ************
        //  PROPERTIES
        // ************
        public string SkinVirtualPath
        {
            get { return skinVirtualPath; }
            set { skinVirtualPath = value; }
        }
        // *********
        //  METHODS
        // *********
        protected override void CreateChildControls()
        {
            Controls.Clear();
            base.CreateChildControls();
            try
            {
                // Try to load the skin
                PreInitialize();
                // Add the skin to the ControlCollection
                Controls.Add( skinControl );
                // Initialize the skin
                Initialize( skinControl );
            }
            catch {} // Prevent application from breaking
        }
        private void PreInitialize()
        {
            skinControl = Page.LoadControl( skinVirtualPath );
        }
        protected abstract void Initialize(Control skinControl);
    }
}

As you can see our base class derives from Control class and implements the interface INamingContainer. The reason we implement INamingContainer is that it makes sure our controls are named in a hierarchical, correct manner.

The first thing after declaring the namespace and class is to add 2 variables which we will use to store the actual skin control with and the virtual path to the skin file. After this is taken care of we expose a public property called SkinVirtualPath. This property will allow page developers to get and set the virtual path to the skin file - each control will need to have this set in order for the control to work.

Next on the agenda is the part where we override CreateChildControls method and do a little action – first off we clear the control collection by performing a call to Controls.Clear() method, and then we do a call to the base class' CreateChildControls method. Once this is over with we need to add our actual skinning methods, namely PreInitialize and Initialize and we need to add the skin control to the control collection. PreInitialize in its current state does nothing more than instantiating skinControl variable by using the method Page.LoadControl. This method takes 1 parameter - a string that point to the virtual path where the user control resides. The Initialize method is abstract because it needs to be specifically overridden by each control that derives from SkinControl. This is because each skin uses its own set of html- and web controls and thus trying to find controls that might not exist make no sense…