我目前的Form1.cs太大了，所以我试图把它们分成多个小文件，这样代码更容易阅读。然而，我的方法可以满足我的需要，但同时也很烦人，因为我的每一个扩展都被视为一个表单。因此，如果我双击扩展，弹出的是一个表单而不是类。所以我必须继续点击然后按F7。请提供解决方案
Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            test();
        }
    }
}

Form1_Ext.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WindowsFormsApplication2
{
    public partial class Form1 
    {
        public void test()
        {
            Console.WriteLine("hello");
        }
    }
}

Form1.Desginer.cs

namespace WindowsFormsApplication2
{
    partial class Form1
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form 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()
        {
            this.components = new System.ComponentModel.Container();
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.Text = "Form1";
        }

        #endregion
    }
}

请看红框，任何扩展类都被视为它自己的形式而不是类。在min时，它应该指向Form1.cs，但它不是。