ComboBox 自動調整組合框下拉部分的寬度

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

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            #region
            InitializeComponent();
            this.Text = Environment.UserName;
            this.StartPosition = FormStartPosition.CenterScreen; // 在桌面居中顯示。
            comboBox1.DataSource = Enum.GetNames(typeof(KnownColor));
            #endregion
        }

        protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);
            foreach (string text in comboBox1.Items)
            {
                comboBox1.DropDownWidth = Math.Max(comboBox1.DropDownWidth, TextRenderer.MeasureText(text, comboBox1.Font).Width);
            }
            comboBox1.ClientSize = new Size(comboBox1.DropDownWidth, comboBox1.ClientSize.Height);
        }
    }
}