(初学版)多国语言中动态加载语言dll

转载请标明是引用于 http://blog.csdn.net/chenyujing1234

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应用背景：

有的软件可能在不同的国家被用，那么就根据不同的国家选择不同的语言dll.(新建一个项目把资源信息编译成一个dll)。 在什么时候加载不同的dll呢?

实现方法：

从注册表中读出所用的语言类型(可以是在安装软件时用户设置的)，然后验证版本相对应，如果对应那么就加载此语言dll作为项目资源句柄。

第一步：从注册表中读出语言种类.

bool GetLanguageFromRegistry(WCHAR* buffer, int SizeBytes)
{
	HKEY key;
	DWORD szType = REG_SZ;
	DWORD szSize = SizeBytes;
	bool ret = false;

	if(RegOpenKeyEx(HKEY_CURRENT_USER, L"Software\\IDS\\uEye\\uEye camera demo\\Language", 0, KEY_READ, &key) == ERROR_SUCCESS)
	{
		if(RegQueryValueEx(key, L"Language", NULL, &szType, (LPBYTE)buffer, &szSize) == ERROR_SUCCESS)
		{	
			ret = true;
		}

		RegCloseKey(key);
	}

	else
	{
		LANGID language = GetSystemDefaultLangID();	
		LANGID english = MAKELANGID(LANG_ENGLISH, SUBLANG_DEFAULT);
		LANGID german = MAKELANGID(LANG_GERMAN, SUBLANG_DEFAULT);
		
		CString Str;
		if(language == english)
			Str.LoadString(IDS_LANGUAGE_ENGLISH);
		else if(language == german)
			Str.LoadString(IDS_LANGUAGE_GERMAN);
		else
			Str.LoadString(IDS_LANGUAGE_ENGLISH);

		wcscpy(buffer, Str);
		
		if(RegCreateKeyEx(HKEY_CURRENT_USER, L"Software\\IDS\\uEye\\uEye camera demo\\Language", 0, 0, 0, KEY_ALL_ACCESS, NULL, &key, 0) == ERROR_SUCCESS)
		{
			RegSetValueEx(key, L"Language", NULL, REG_SZ, (LPBYTE)buffer, sizeof(buffer));		
			RegCloseKey(key);
			ret = true;
		}
	}

	return ret;
}

第二步：验证资源的dll版本号与应用程序的版本号是否对上.

bool SearchLanguageDll(WCHAR* file)
{
	bool ret = false;
	WCHAR DemoVersion[20];
	WCHAR DllVersion[20];

	GetDemoVersion(DemoVersion);
	if(GetLanguageDllVersion(file, DllVersion) == true)
	{
		if(wcscmp(DemoVersion, DllVersion) == 0)
			ret = true;
	}

	return ret;
}

bool GetDemoVersion(WCHAR* Result)
{
	bool ret = false;

	// Get the path to this program
	WCHAR buffer[MAX_PATH];
	GetModuleFileName(NULL, buffer, MAX_PATH);

	CString Str;
	DWORD dwSize = 0;
	DWORD dwHandle;

	dwSize = GetFileVersionInfoSize (buffer, &dwHandle);
	if(dwSize != 0)
	{
		WCHAR* pc = new WCHAR[dwSize];
		if(pc != NULL)
		{
			if(GetFileVersionInfo(buffer, 0, dwSize, pc))
			{
				VS_FIXEDFILEINFO* pfi;
				int nLen;
				if (VerQueryValue (pc, L"\\", (void**) &pfi, (PUINT) &nLen) )
				{
					swprintf(Result, L"%d.%d.%d", (pfi->dwFileVersionMS & 0xFFFF0000L)>>16,
												  (pfi->dwFileVersionMS & 0xFFFFL),
												  (pfi->dwFileVersionLS & 0xFFFF0000L)>>16);
					/*
					swprintf(Result, L"%d.%d.%d.%d",  (pfi->dwFileVersionMS & 0xFFFF0000L)>>16,
												 	 (pfi->dwFileVersionMS & 0xFFFFL),
												 	 (pfi->dwFileVersionLS & 0xFFFF0000L)>>16,
													 (pfi->dwFileVersionLS & 0xFFFFL) );
					*/

					ret = true;
				}
			}
		}

		delete[] pc;
		pc = NULL;
	}

	return ret;
}


bool GetLanguageDllVersion(const WCHAR* File, WCHAR* Result)
{
	bool ret = false;
		
	DWORD dwSize = 0;
	DWORD dwHandle;

	dwSize = GetFileVersionInfoSize ((WCHAR*)File, &dwHandle);

	if(dwSize != 0)
	{
		WCHAR* pc = new WCHAR[dwSize];
		if(pc != NULL)
		{
			if(GetFileVersionInfo((WCHAR*)File, 0, dwSize, pc))
			{
				VS_FIXEDFILEINFO* pfi;
				int nLen;
				if (VerQueryValue (pc, L"\\", (void**) &pfi, (PUINT) &nLen) )
				{
					swprintf(Result, L"%d.%d.%d", (pfi->dwFileVersionMS & 0xFFFF0000L)>>16,
											 	  (pfi->dwFileVersionMS & 0xFFFFL),
											      (pfi->dwFileVersionLS & 0xFFFF0000L)>>16);
					/*
					swprintf(Result, L"%d.%d.%d.%d",  (pfi->dwFileVersionMS & 0xFFFF0000L)>>16,
												 	  (pfi->dwFileVersionMS & 0xFFFFL),
													  (pfi->dwFileVersionLS & 0xFFFF0000L)>>16,
													  (pfi->dwFileVersionLS & 0xFFFFL) );
					*/
					ret = true;
				}
			}
		}

		delete[] pc;
		pc = NULL;
	}

	return ret;
}

第三步：加载dll作为资源句柄

HINSTANCE Lang = LoadLibrary(LanguageDll);
			if(Lang != NULL)
				AfxSetResourceHandle(Lang);