设置PATH环境变量，及CRegKey类的使用

设置PATH环境变量，注意缓冲区指针的类型

lpSetValue = (LPBYTE)TEXT(lpszSet);
dwCount = strlen(lpszSet) + 1;
dwType = REG_SZ;
if(ERROR_SUCCESS == RegSetValueEx(hkey, TEXT("PATH"), NULL, dwType, lpSetValue, dwCount)){
fModified = TRUE;
}
注意：直接lpSetValue = (LPBYTE)lpszSet时%xxx%变量将不会被自动替换!

修改之后，通知所有应用环境变量已经改变

SendMessageTimeout(HWND_BROADCAST,WM_SETTINGCHANGE,0,(LPARAM)"Environment",SMTO_ABORTIFHUNG,500,&dwDisposition);

函数getenv不好用，总是返回win系统启动时的环境；可能GetEnvironmentVariable要好用些，需要继续测试才知道...

---------------------------------------------------
以下的使用CRegKey的实现
---------------------------------------------------

// EnvManager.h: interface for the CEnvManager class.
//
//////////////////////////////////////////////////////////////////////

#if !defined(AFX_ENVMANAGER_H__C4B551D3_3E8C_43F7_BF77_E76288246BC7__INCLUDED_)
#define AFX_ENVMANAGER_H__C4B551D3_3E8C_43F7_BF77_E76288246BC7__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#include <string>

using namespace std;

class CEnvManager
{
public:
CEnvManager();
virtual ~CEnvManager();

public:
VOID SetPrjName(LPSTR name);
VOID SetWorkPath(LPSTR lpszCmdLine);
BOOL verify(LPSTR lpszCmdLine = NULL);
void Delete();
void SetInt();
void SetStr();
void GetStr();
void GetInt();

private:
string errmsg;
string workpath;
string prjname;
};

#endif // !defined(AFX_ENVMANAGER_H__C4B551D3_3E8C_43F7_BF77_E76288246BC7__INCLUDED_)

// EnvManager.cpp: implementation of the CEnvManager class.
//
//////////////////////////////////////////////////////////////////////
#include "StdAfx.h"

#include <atlbase.h>
#include "sdk_env.h"
#include "sdk_macro.h"

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CEnvManager::CEnvManager()
{

}

CEnvManager::~CEnvManager()
{

}

VOID CEnvManager::SetWorkPath(LPSTR lpszCmdLine)
{
workpath = lpszCmdLine;
}

VOID CEnvManager::SetPrjName(LPSTR name)
{
prjname = name;
}

// 用CRegKey类来操作注册表是非常方便的。CRegKey类并不是一个MFC类，而是一个ATL类，
// 所以在使用的时候不要忘记在StdAfx.h头文件中加入#include <atlbase.h>。

void CEnvManager::GetInt()
{
// 获取注册表中整数值
CRegKey rk;
DWORD dwValue;
CString strTemp;
LPCTSTR lpszKeyName = _T ("Software//Microsoft//Windows//CurrentVersion//Explorer");

if (rk.Open (HKEY_CURRENT_USER, lpszKeyName) == ERROR_SUCCESS)
{
TRACE0 ("Open Success./n");
if (rk.QueryValue (dwValue, _T ("Browse For Folder Height")) == ERROR_SUCCESS)
{
TRACE0 ("Query Success./n");
strTemp.Format ("%0X", dwValue);
}
}
rk.Close();
}

void CEnvManager::GetStr()
{
// 获取注册表中字符串值
CRegKey rk;
DWORD dwCount = 1024;
CString strTemp;
TCHAR szValue [1024];
// LPCTSTR lpszKeyName = _T ("Software//Microsoft//Windows//CurrentVersion//Explorer");

// if (rk.Open (HKEY_CURRENT_USER, lpszKeyName) == ERROR_SUCCESS)
// {
// TRACE0 ("Open Success./n");
// if (rk.QueryValue (szValue, _T ("Logon User Name"), &dwCount) == ERROR_SUCCESS)
// {
// TRACE0 ("Query Success./n");
// strTemp = szValue;
// }
// }
rk.Close();
}

void CEnvManager::SetStr()
{
// 设置注册表中字符串值
CRegKey rk;
LPCTSTR lpszKeyName = _T ("Software//JueYuanLongStudio//Test");

// Create能在Open失败的情况下自动尝试建立
if (rk.Create (HKEY_CURRENT_USER, lpszKeyName) == ERROR_SUCCESS)
{
TRACE0 ("Open Success./n");
if (rk.SetValue (_T ("palagon"), _T ("Logon User Name")) == ERROR_SUCCESS)
{
TRACE0 ("SetValue Success./n");
}
}
rk.Close();
}

void CEnvManager::SetInt()
{
// 设置注册表中数据值
CRegKey rk;
LPCTSTR lpszKeyName = _T ("Software//JueYuanLong Studio//Test");

// Create能在Open失败的情况下自动尝试建立
if (rk.Create (HKEY_CURRENT_USER, lpszKeyName) == ERROR_SUCCESS)
{
TRACE0 ("Open Success./n");
if (rk.SetValue (110, _T ("Logon User Data")) == ERROR_SUCCESS)
{
TRACE0 ("SetValue Success./n");
}
}
rk.Close();
}

void CEnvManager::Delete()
{
// 删除注册表中键值
CRegKey rk;
LPCTSTR lpszKeyName = _T ("Software//JueYuanLong Studio//Test");

// Create能在Open失败的情况下自动尝试建立
if (rk.Create (HKEY_CURRENT_USER, lpszKeyName) == ERROR_SUCCESS)
{
TRACE0 ("Open Success./n");
if (rk.DeleteValue (_T ("Logon User Data")) == ERROR_SUCCESS)
{
TRACE0 ("DeleteValue Success./n");
}
}
rk.Close();
}

BOOL CEnvManager::verify(LPSTR lpszCmdLine)
{
TCHAR szKey[5120]= {0};

// get project name
SetPrjName((CHAR *)szKey);
// get work directory
SetWorkPath(GetCommandLine());

// verify project name & work directory
if (prjname.size() <= 0) {
return FALSE;
} else if (workpath.size() <= 0) {
return FALSE;
}

LPCTSTR lpszKeyEnv = _T ("SYSTEM//CurrentControlSet//Control//Session Manager//Environment");
CRegKey rk;
BOOL fModified = FALSE;
CString strAcs;
CString strTmp;
DWORD dwCount = sizeof(szKey);

// open enviroment registry key
if (rk.Open (HKEY_LOCAL_MACHINE, lpszKeyEnv) != ERROR_SUCCESS) {
errmsg = "Cann't open HKEY_LOCAL_MACHINE !";
return FALSE;
}

memset(szKey, 0, sizeof(szKey));
dwCount = sizeof(szKey);
if (rk.QueryValue (szKey, _T ("PATH"), &dwCount) == ERROR_SUCCESS) {
strAcs = szKey;
} else {
strAcs.Empty();
}
rk.Close();

return TRUE;
}