C# ComboBox 枠に色をつける

using System.Windows.Forms;
using System.Drawing;

namespace ProductionManagement
{
    class BorderComboBox : ComboBox
    {
        private Color _BorderColor = Color.White;
        private ButtonBorderStyle _BorderStyle = ButtonBorderStyle.None;

        protected override void WndProc(ref Message m)
        {
            base.WndProc(ref m);

            if(m.Msg == 0x000F)
            {
                Graphics g = Graphics.FromHwnd(Handle);
                Rectangle b = new Rectangle(0, 0, Width, Height);
                ControlPaint.DrawBorder(g, b, _BorderColor, _BorderStyle);
            }
        }

        public Color BorderColor
        {
            get { return _BorderColor; }
            set { _BorderColor = value; Invalidate(); }
        }

        public ButtonBorderStyle BorderStyle
        {
            get { return _BorderStyle; }
            set { _BorderStyle = value; Invalidate(); }
        }

    }
}

using System.Windows.Forms;

using System.Drawing;

namespace ProductionManagement

{

class BorderComboBox : ComboBox

{

private Color _BorderColor = Color.White;

private ButtonBorderStyle _BorderStyle = ButtonBorderStyle.None;

protected override void WndProc(ref Message m)

{

base.WndProc(ref m);

if(m.Msg == 0x000F)

{

Graphics g = Graphics.FromHwnd(Handle);

Rectangle b = new Rectangle(0, 0, Width, Height);

ControlPaint.DrawBorder(g, b, _BorderColor, _BorderStyle);

}

public Color BorderColor

{

get { return _BorderColor; }

set { _BorderColor = value; Invalidate(); }

}

public ButtonBorderStyle BorderStyle

{

get { return _BorderStyle; }

set { _BorderStyle = value; Invalidate(); }

}