C#：程序只打开一次，再打开自动激活之前打开的

简单点。

直接上代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Diagnostics;

namespace Test
{
    static class Program
    {
        /// 

        /// 应用程序的主入口点。
        /// 
        [STAThread]
        static void Main()
        {
            Process process = GetRunningProcess();
            if (process != null)
            {
                ShowRunningApplication(process);
            }
            else
            {
                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);
                Application.Run(new Form1());
            }
        }

        /// 

        /// 获取已运行的进程，未运行返回null
        /// 
        /// 
        private static Process GetRunningP