1、登录实现

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 LoginApp
{
    public partial class LoginForm : Form
    {
        public LoginForm()
        {
            InitializeComponent();
        }

        private void BtnLogin_Click(object sender, EventArgs e)
        {
            if(this.tbUsername.Text.Equals("engineer") && this.tbPassword.Text.Equals("123456"))
            {
                MainForm mainForm = new MainForm();
                this.Hide();
                mainForm.ShowDialog();
                this.Close();
            }
        }
    }
}

2、工具栏切换

using LoginApp.ToolUs;
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 LoginApp
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
        }

        private void BtnComponent_Click(object sender, EventArgs e)
        {
            Button btn = (Button)sender;
            UserControl userControl = new UserControl();
            switch(btn.Text)
            {
                case "器件":
                    userControl = new Device();
                    break;
                case "连接":
                    userControl = new Connection();
                    break;
            }
            userControl.BackColor = Color.White;
            userControl.Dock = DockStyle.Fill;
            tableLayoutPanel2.Controls.Add(userControl, 1, 0);
        }
    }
}

3、运行