Windows API一日一练(63)RegOpenKeyEx和RegCreateKeyEx函数

由于电脑经常会关闭，或者应用程序也会经常关闭，但有一些参数是经常需要保存。比如当你打开程序，并设置了窗口的大小，想每次打开时都设置窗口为上次打开的大小。这样就需要保存窗口的大小，那么窗口大小的参数保存到那里呢？其实在Windows里最方便的做法，就是保存到注册表里。又比如游戏登录时，总是想保存最后一个登录的用户，那么也需要保存这个用户到注册表里。其实注册表是Windows保存系统配置的数据库，比如不同的语言设置，不同的时区设置，不同的用户登录，不同的权限等等。下面就来学习怎么样使用函数RegOpenKeyEx来打开注册表里的键和用函数RegCreateKeyEx来创建新的键。 函数RegOpenKeyEx和RegCreateKeyEx声明如下： WINADVAPILONGAPIENTRYRegOpenKeyExA (    __in HKEY hKey,    __in_opt LPCSTR lpSubKey,    __reserved DWORD ulOptions,    __in REGSAM samDesired,    __out PHKEY phkResult    );WINADVAPILONGAPIENTRYRegOpenKeyExW (    __in HKEY hKey,    __in_opt LPCWSTR lpSubKey,    __reserved DWORD ulOptions,    __in REGSAM samDesired,    __out PHKEY phkResult    );#ifdef UNICODE#define RegOpenKeyEx RegOpenKeyExW#else#define RegOpenKeyEx RegOpenKeyExA#endif // !UNICODE  WINADVAPILONGAPIENTRYRegCreateKeyExA (    __in HKEY hKey,    __in LPCSTR lpSubKey,    __reserved DWORD Reserved,    __in_opt LPSTR lpClass,    __in DWORD dwOptions,    __in REGSAM samDesired,    __in_opt LPSECURITY_ATTRIBUTES lpSecurityAttributes,    __out PHKEY phkResult,    __out_opt LPDWORD lpdwDisposition    );WINADVAPILONGAPIENTRYRegCreateKeyExW (    __in HKEY hKey,    __in LPCWSTR lpSubKey,    __reserved DWORD Reserved,    __in_opt LPWSTR lpClass,    __in DWORD dwOptions,    __in REGSAM samDesired,    __in_opt LPSECURITY_ATTRIBUTES lpSecurityAttributes,    __out PHKEY phkResult,    __out_opt LPDWORD lpdwDisposition    );#ifdef UNICODE#define RegCreateKeyEx RegCreateKeyExW#else#define RegCreateKeyEx RegCreateKeyExA#endif // !UNICODE hKey是主键。lpSubKey是子键。ulOptions是选项。samDesired是键的操作。phkResult是打开的键返回。lpClass是新键值。 调用函数的例子如下：#001 //打注册表。HKEY_CURRENT_USER/"Software"/"Wincpp"/"testreg"#002  //蔡军生 2007/11/02 QQ:9073204 深圳#003  HKEY GetAppRegistryKey(void)#004  {#005         HKEY hAppKey = NULL;#006         HKEY hSoftKey = NULL;#007         HKEY hCompanyKey = NULL;#008 #009         //打开HKEY_CURRENT_USER/"Software"。#010        if (RegOpenKeyEx(HKEY_CURRENT_USER, _T("software"), 0, KEY_WRITE|KEY_READ,#011              &hSoftKey) == ERROR_SUCCESS)#012         {#013               DWORD dw;#014               //创建并打开HKEY_CURRENT_USER/"Software"/"Wincpp"#015              if (RegCreateKeyEx(hSoftKey, _T("Wincpp"), 0, REG_NONE,#016                   REG_OPTION_NON_VOLATILE, KEY_WRITE|KEY_READ, NULL,#017                   &hCompanyKey, &dw) == ERROR_SUCCESS)#018               {#019                    //创建并打开HKEY_CURRENT_USER/"Software"/"Wincpp"/"testreg"#020                    RegCreateKeyEx(hCompanyKey, _T("testreg"), 0, REG_NONE,#021                          REG_OPTION_NON_VOLATILE, KEY_WRITE|KEY_READ, NULL,#022                          &hAppKey, &dw);#023               }#024         }#025 #026         //关闭打开的键值。#027         if (hSoftKey != NULL)#028         {#029               RegCloseKey(hSoftKey);#030         }    #031 #032         if (hCompanyKey != NULL)#033         {#034               RegCloseKey(hCompanyKey);#035         }    #036 #037         return hAppKey;#038  }