Hi

Here is my test code for your reference, you may have a try and let me know
the result.

using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Windows.Forms;

namespace CustomControlButton
{
    /// <summary>
    /// Summary description for UserControl1.
    /// </summary>
    public class CustomButton : System.Windows.Forms.Button
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.Container components = null;

        public CustomButton()
        {
            // This call is required by the Windows.Forms Form Designer.
            InitializeComponent();

            // TODO: Add any initialization after the InitComponent call

        }

        protected override bool ShowFocusCues
        {
            get
            {
                return false;
            }
        }
        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if( components != null )
                    components.Dispose();
            }
            base.Dispose( disposing );
        }

        #region Component Designer generated code
        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            //
            // UserControl1
            //
            this.Name = "CustomButton";

        }
        #endregion
    }
}

Best regards,

Peter Huang
Microsoft Online Partner Support