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

public class IpTextBox : TextBox
{
    public IpTextBox()
    {
        Font = base.Font;
    }

    public override sealed Font Font
    {
        get { return base.Font; }
        set
        {
            base.Font = (Font)value.Clone();
        }
    }

    protected override CreateParams CreateParams
    {
        get
        {
            CreateParams cp = base.CreateParams;
            cp.ClassName = "SysIPAddress32";
            return cp;
        }
    }

    protected override bool IsInputKey(Keys keyData)
    {
        return (base.IsInputKey(keyData) || keyData == Keys.Left || keyData == Keys.Right);
    }
}