C#实现程序在系统托盘显示图标及开机自启动

# 引言
我们在使用桌面应用程序时，经常会看到一些程序在系统托盘中显示图标，且会有一些常用功能。如QQ、钉钉、微信等，同时，这些程序在系统启动后也跟随自动启动。本文将介绍C#实现程序在系统托盘中显示图标及开机自启动的内容。
# 实现
**1、程序在系统托盘中显示图标**

NotifyIcon 控件，通常用于在系统托盘中显示图标，通过使用它就可以我们想要的效果。

**常用属性**

| 属性 | 描述 | 其他 |
| --- | --- | --- |
|Icon  |在系统托盘中显示的图标  |  |
|Text | 鼠标悬停在图标时显示的文本 |  |
|Visible  |指定是否可见  |  |

**常用方法**

| 属性 | 描述 | 其他 |
| --- | --- | --- |
| ShowContextMenu | 在系统托盘上下文菜单中显示指定的菜单
| --- |

**实现步骤**

1、创建 NotifyIcon 控件并设置属性；
2、编写 NotifyIcon 响应控制事件；
3、在主窗体的Load事件中将 NotifyIcon 添加到系统托盘；
4、程序退出时，移除系统托盘的 NotifyIcon；

```java
using System;
using System.Windows.Forms;

namespace Fountain.WinForm.NotifyDemo
{
    public partial class FormMain : Form
    {
        /// <summary>
        /// 通知控件
        /// </summary>
        private NotifyIcon notifyIcon = new NotifyIcon();
        /// <summary>
        /// 通知控件显示菜单
        /// </summary>
        private ContextMenuStrip contextMenuStrip = new ContextMenuStrip();
        /// <summary>
        /// 构造方法
        /// </summary>
        public FormMain()
        {
            InitializeComponent();
        }
        /// <summary>
        /// 窗体加载
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void FormMain_Load(object sender, EventArgs e)
        {
            this.InitializeNotifyMenu();
            this.notifyIcon.Text = this.Text;
            this.notifyIcon.Visible = true;
            this.notifyIcon.Icon = this.Icon;
            this.notifyIcon.ContextMenuStrip = this.contextMenuStrip;
            this.notifyIcon.DoubleClick += notifyIcon_DoubleClick;
        }
        /// <summary>
        /// 托盘菜单
        /// </summary>
        private void InitializeNotifyMenu()
        {
            try
            {
                contextMenuStrip.Items.Clear();
                ToolStripMenuItem showMenuItem = new ToolStripMenuItem("显示界面");
                showMenuItem.Tag = "显示";
                showMenuItem.Click += new EventHandler(ShowMenuItem_Click);
                contextMenuStrip.Items.Add(showMenuItem);

ToolStripMenuItem sboutMenuItem = new ToolStripMenuItem("关于");
                sboutMenuItem.Tag = "关于";
                sboutMenuItem.Click += new EventHandler(AboutMenuItem_Click);
                contextMenuStrip.Items.Add(sboutMenuItem);

ToolStripMenuItem exitMenuItem = new ToolStripMenuItem("退出");
                exitMenuItem.Tag = "退出";
                exitMenuItem.Click += new EventHandler(ExistMenuItem_Click);
                contextMenuStrip.Items.Add(exitMenuItem);
            }
            catch(Exception exception) 
            {
                throw new Exception(exception.Message);
            }
        }
        /// <summary>
        /// 右击任务栏图标
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void notifyIcon_DoubleClick(object sender, EventArgs e)
        {
            try
            {
                if (this.WindowState == FormWindowState.Normal)
                {
                    this.WindowState = FormWindowState.Minimized;
                    this.Hide();
                }
                else if (this.WindowState == FormWindowState.Minimized)
                {
                    this.Show();
                    this.WindowState = FormWindowState.Normal;
                    this.Activate();
                }
            }
            catch (Exception objException)
            {
                throw new Exception(objException.Message);
            }
        }
        /// <summary>
        /// 显示
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void ShowMenuItem_Click(object sender, EventArgs e)
        {
            try
            {
                this.Show();
                this.WindowState = FormWindowState.Normal;
                this.Activate();
            }
            catch (Exception objException)
            {
                throw new Exception(objException.Message);
            }
        }
        /// <summary>
        /// 关于
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void AboutMenuItem_Click(object sender, EventArgs e)
        {
            try
            {
            }
            catch (Exception objException)
            {
                MessageBox.Show(objException.Message);
            }
        }
        /// <summary>
        /// 退出
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void ExistMenuItem_Click(object sender, EventArgs e)
        {
            try
            {
                if (MessageBox.Show("你确定要退出程序吗？","提示", MessageBoxButtons.OKCancel, MessageBoxIcon.Question, MessageBoxDefaultButton.Button2) == DialogResult.OK)
                {
                    this.notifyIcon.Visible = false;
                    this.notifyIcon.Dispose();
                    this.Dispose();
                    Application.Exit();
                }
            }
            catch (Exception objException)
            {
                MessageBox.Show(objException.Message);
            }
        }
        /// <summary>
        /// 主窗体关闭
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void FormMain_FormClosing(object sender, FormClosingEventArgs e)
        {
            try
            {
                e.Cancel = true;
                this.Hide();
                this.notifyIcon.Dispose();
            }
            catch (Exception objException)
            {
                MessageBox.Show(objException.Message);
            }
        }
        /// <summary>
        /// 窗体大小变化
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void FormMain_Resize(object sender, EventArgs e)
        {
            if (this.WindowState == FormWindowState.Minimized)
            {
                this.ShowInTaskbar = false;
                this.Hide();
                this.notifyIcon.Visible = true;
            }
        }
    }
}
```
2、系统开机自启动应用程序
通过将应用程序往注册表开机启动项，实现开机自启动。下面通过示例介绍其实现。

```java
using Microsoft.Win32;
using System;
using System.Diagnostics;
using System.Windows.Forms;

namespace Fountain.WinForm.NotifyDemo
{
    public partial class FormMain : Form
    {
        /// <summary>
        /// 构造方法
        /// </summary>
        public FormMain()
        {
            InitializeComponent();
        }
        /// <summary>
        /// 窗体加载
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void FormMain_Load(object sender, EventArgs e)
        { 
            string applictionName = Process.GetCurrentProcess().MainModule.ModuleName;
            string applictionPath = Process.GetCurrentProcess().MainModule.FileName;
            #region 当前登陆用户的注册表启动项
            RegistryKey registryKey = Registry.CurrentUser.CreateSubKey(@"SOFTWARE\Microsoft\Windows\CurrentVersion\Run");
            registryKey.SetValue(applictionName, applictionPath);
            #endregion
            #region 所有用户的注册表启动项
            //RegistryKey registryKey = Registry.LocalMachine.CreateSubKey(@"SOFTWARE\Microsoft\Windows\CurrentVersion\Run");
            //registryKey.SetValue(applictionName, applictionPath);
            #endregion
        }
    }
}
```