using Microsoft.Win32;

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Diagnostics;

using System.Drawing;

using System.IO;

using System.Runtime.InteropServices;

using System.Text;

using System.Windows.Forms;

namespace WindowsForms设置系统变量

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void button1_Click(object sender, EventArgs e)

        {

            //var str =  SysEnvironment.GetSysEnvironmentByName("Path"); //系统变量 Path

            //  SysEnvironment.SetSysEnvironment("Path", "0");

            //HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Session Manager\Environment 下的Path值

            SysEnvironment.SetPathAfter(@"C:\mysql\bin");

            MessageBox.Show("完成!" + @"C:\mysql\bin;");

            var str = SysEnvironment.GetSysEnvironmentByName("Path"); //系统变量 Path

            string[] temp = str.Split(new char[] { ';' }, StringSplitOptions.RemoveEmptyEntries);

            for (int i = ; i < temp.Length; i++)

            {

                textBox1.Text += temp[i] + "\r\n";

            }

        }

        private void button2_Click(object sender, EventArgs e)

        {

            ////RunCmd(@"C:\Windows\System32\","ipconfig");

            //System.Diagnostics.Process.Start(@"C:\Windows\System32\cmd.exe");

            //textBox2.Text += Cmd(@"CD C:\mysql  mysqld --defaults-file=my.ini --initialize-insecure");

        }

        ///<summary>

        /// cmd命令执行，在cmd上可以执行的语句，直接传到这里，调用grads画图实例如下：

        ///  Cmd("C:/OpenGrADS/Contents/Cygwin/Versions/2.0.1.oga.1/i686/grads.exe -lbcx 'D:/data_wrfchem/gs/d01_hour_pm25.gs D:/data_wrfchem 2016-04-18 d01'");

        ///  Cmd("grads启动程序exe路径 -lbcx 'gs脚本文件 参数1 参数2 参数3'");

        /// </summary>

        /// <param name="c">执行语句</param>

        public string Cmd(string c)

        {

            System.Diagnostics.Process process = new System.Diagnostics.Process();

            process.StartInfo.FileName = "cmd.exe";

            process.StartInfo.UseShellExecute = false;

            process.StartInfo.CreateNoWindow = true;

            process.StartInfo.RedirectStandardOutput = true;

            process.StartInfo.RedirectStandardInput = true;

            process.Start();

            process.StandardInput.WriteLine(c);

            process.StandardInput.AutoFlush = true;

            process.StandardInput.WriteLine("exit");

            StreamReader reader = process.StandardOutput;//截取输出流

            //string output = reader.ReadLine();//每次读取一行

            //while (!reader.EndOfStream)

            //{

            //    // PrintThrendInfo(output);

            //    output = reader.ReadLine();

            //}

            string output = reader.ReadToEnd();//每次读取一行

            process.WaitForExit();

            return output;

        }

    }

    public static class SysEnvironment

    {

        #region --获取注册表中的环境变量

        /// <summary>

        /// 获取系统环境变量

        /// </summary>

        /// <param name="name"></param>

        /// <returns></returns>

        public static string GetSysEnvironmentByName(string name)

        {

            string result = string.Empty;

            try

            {

                result = OpenSysEnvironment().GetValue(name).ToString();//读取

            }

            catch (Exception)

            {

                return string.Empty;

            }

            return result;

        }

        /// <summary>

        /// 打开系统环境变量注册表

        /// </summary>

        /// <returns>RegistryKey</returns>

        private static RegistryKey OpenSysEnvironment()

        {

            RegistryKey regLocalMachine = Registry.LocalMachine;

            RegistryKey regSYSTEM = regLocalMachine.OpenSubKey("SYSTEM", true);//打开HKEY_LOCAL_MACHINE下的SYSTEM

            RegistryKey regControlSet001 = regSYSTEM.OpenSubKey("ControlSet001", true);//打开ControlSet001

            RegistryKey regControl = regControlSet001.OpenSubKey("Control", true);//打开Control

            RegistryKey regManager = regControl.OpenSubKey("Session Manager", true);//打开Control 

            RegistryKey regEnvironment = regManager.OpenSubKey("Environment", true);

            return regEnvironment;

        }

        /// <summary>

        /// 设置系统环境变量

        /// </summary>

        /// <param name="name">变量名</param>

        /// <param name="strValue">值</param>

        public static void SetSysEnvironment(string name, string strValue)

        {

            OpenSysEnvironment().SetValue(name, strValue);

        }

        #endregion

        /// <summary>

        /// 检测系统环境变量是否存在

        /// </summary>

        /// <param name="name"></param>

        /// <returns></returns>

        public static bool CheckSysEnvironmentExist(string name)

        {

            if (!string.IsNullOrEmpty(GetSysEnvironmentByName(name)))

                return true;

            else

                return false;

        }

        /// <summary>

        /// 添加到PATH环境变量（会检测路径是否存在，存在就不重复）

        /// </summary>

        /// <param name="strPath"></param>

        public static void SetPathAfter(string strHome)

        {

            string pathlist;

            pathlist = GetSysEnvironmentByName("PATH");

            bool isPathExist = false;

            if (pathlist.Length > )

            {

                //检测是否以;结尾

                if (pathlist.Substring(pathlist.Length - , ) != ";") //截取最后一个字符,判断这个字符不等于;号,

                {

                    SetSysEnvironment("PATH", pathlist + ";");

                    pathlist = GetSysEnvironmentByName("PATH");

                }

                string[] list = pathlist.Split(';');//以;切割

                foreach (string item in list)

                {

                    if (item == strHome)

                        isPathExist = true;

                }

            }

            if (!isPathExist)

            {

                SetSysEnvironment("PATH", pathlist + strHome + ";");

            }

        }

        public static void SetPathBefore(string strHome)

        {

            string pathlist;

            pathlist = GetSysEnvironmentByName("PATH");

            string[] list = pathlist.Split(';');

            bool isPathExist = false;

            foreach (string item in list)

            {

                if (item == strHome)

                    isPathExist = true;

            }

            if (!isPathExist)

            {

                SetSysEnvironment("PATH", strHome + ";" + pathlist);

            }

        }

        public static void SetPath(string strHome)

        {

            string pathlist;

            pathlist = GetSysEnvironmentByName("PATH");

            string[] list = pathlist.Split(';');

            bool isPathExist = false;

            foreach (string item in list)

            {

                if (item == strHome)

                    isPathExist = true;

            }

            if (!isPathExist)

            {

                SetSysEnvironment("PATH", pathlist + strHome + ";");

            }

        }

    }

    //Kernel32.DLL内有SetEnvironmentVariable函数用于设置系统环境变量

    //C#调用要用DllImport，代码封装如下：

    class SetSysEnvironmentVariable

    {

        [DllImport("Kernel32.DLL ", SetLastError = true)]

        public static extern bool SetEnvironmentVariable(string lpName, string lpValue);

        public static void SetPath(string pathValue)

        {

            string pathlist;

            pathlist = SysEnvironment.GetSysEnvironmentByName("PATH");

            string[] list = pathlist.Split(';');

            bool isPathExist = false;

            foreach (string item in list)

            {

                if (item == pathValue)

                    isPathExist = true;

            }

            if (!isPathExist)

            {

                SetEnvironmentVariable("PATH", pathlist + pathValue + ";");

            }

        }

    }

}