当前路径：Cool.Windows.Forms/CoolTextBox.cs
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Cool.Windows.Forms
{
    public class CoolTextBox : TextBox
    {
        public CoolTextBox()
        {
      ...