Windows api关于注册表的操作经验和总结

 HKEY hk;   int result = RegOpenKeyEx(HKEY_LOCAL_MACHINE,               _T("SYSTEM//ControlSet001//Control//Session Manager//Environment"),               NULL,               KEY_READ, &hk );   if(result != ERROR_SUCCESS)  {    if(result == ERROR_FILE_NOT_FOUND)    {       MessageBox(g.hwnd,_T("no such key in RegOpenKeyEx"),_T("title"),MB_ICONWARNING);    }     else       return;  }   DWORD lsize;   result = RegQueryValueEx(hk, _T("Path"),NULL,NULL,              NULL, &lsize);    if(result != ERROR_SUCCESS)  {    if(result == ERROR_FILE_NOT_FOUND)    {       MessageBox(g.hwnd,_T("no such key in RegQueryValue"),_T("title"),MB_ICONWARNING);    }    else if(result == ERROR_MORE_DATA)    {      MessageBox(g.hwnd,_T("need more buffer"),_T("title"),MB_ICONWARNING);    }    else       return;  }  TCHAR *value = (TCHAR * )malloc(lsize * sizeof(TCHAR));  result = RegQueryValueEx(hk, _T("Path"),NULL,NULL,              (LPBYTE)value, &lsize);  if(result != ERROR_SUCCESS)  {    if(result == ERROR_FILE_NOT_FOUND)    {       MessageBox(g.hwnd,_T("no such key in RegQueryValue"),_T("title"),MB_ICONWARNING);    }    else if(result == ERROR_MORE_DATA)    {      MessageBox(g.hwnd,_T("need more buffer"),_T("title"),MB_ICONWARNING);    }    else        return;  }  SetWindowText(g.hwndEdit,value);  free(value);  RegCloseKey(hk);