C#读取设置path环境变量并重启计算机[转载]

有时候需要修改path系统环境变量， 不多说，代码如下：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using Microsoft.Win32;//注册表操作要引用的空间
using System.Runtime.InteropServices;//调用API函数需要的引用，来加载非托管类user32.dll

namespace 用程序修改环境变量
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void Form1_Load(object sender, EventArgs e)
{

}
/**////
/// 读取注册表
/// path的路径：[HKEY_LOCAL_MACHINE/SYSTEM/ControlSet001/Control/Session Manager/Environment]
///
///
///
private void tbnRead_Click(object sender, EventArgs e)
{
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);//打开MSSQLServer下的MSSQLServer
this.richTextBox1.Text = regEnvironment.GetValue("path").ToString();//读取path的值
}

private void btnClose_Click(object sender, EventArgs e)
{
Close();
}

/**////
///
///
///
///
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]//SendMessageTimeout是在user32.dll中定义的
public static extern IntPtr SendMessageTimeout(
IntPtr windowHandle,
uint Msg,
IntPtr wParam,
IntPtr lParam,
SendMessageTimeoutFlags flags,
uint timeout,
out IntPtr result
);

[Flags]
public enum SendMessageTimeoutFlags : uint
{
SMTO_NORMAL = 0x0000,
SMTO_BLOCK = 0x0001,
SMTO_ABORTIFHUNG = 0x0002,
SMTO_NOTIMEOUTIFNOTHUNG = 0x0008
}

private void btnWrite_Click(object sender, EventArgs e)
{

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);//打开MSSQLServer下的MSSQLServer
regEnvironment.SetValue("path", this.richTextBox1.Text);//读取path的值

MessageBox.Show("修改成功");
//下面利用发送系统消息，就不要重新启动计算机了
const int HWND_BROADCAST=0xffff;
// DWORD dwMsgResult = 0L;
const uint WM_SETTINGCHANGE = 0;
const long SMTO_ABORTIFHUNG = 0x2;
System.UInt32 dwMsgResult1=0;
long s;
// SendMessageTimeout(HWND_BROADCAST, WM_SETTINGCHANGE, 0, (string)"Environment", SMTO_ABORTIFHUNG, 5000,(long)s);

}
/**////
/// 重新启动计算机
///
///
///
///
[DllImport("user32.dll")]
//主要ＡＰＩ是这个，注意：必须声明为static extern
private static extern int ExitWindowsEx(int x, int y);
private void button1_Click(object sender, EventArgs e)
{
ExitWindowsEx(2,0);
}
}
}