MUI: Sampel Pengaturan Application-Specific (Pra-Windows Vista)

Aplikasi sampel yang dijelaskan dalam topik ini mirip dengan yang ditunjukkan di MUI: Application-Specific Pengaturan Sampel (Windows Vista), kecuali bahwa aplikasi ini akan berjalan pada Windows 2000 dan yang lebih baru. Perbedaan utama dari sampel lain adalah bahwa fallback bahasa harus disesuaikan untuk dijalankan pada beberapa sistem operasi.

Aplikasi ini pertama-tama mengurai daftar bahasa yang dibatasi dalam file teks dan mengonversinya menjadi daftar bahasa multi-string untuk menentukan preferensi bahasa khusus aplikasi. Pemisah yang didukung dalam sampel adalah ",", ";", ":", dan " ". Setelah mengurai daftar, kode menemukan dan memuat sumber daya dalam bahasa yang diidentifikasi. Berbeda dengan sampel pengaturan khusus aplikasi lainnya, kode ini memuat dan merilis file sumber daya menggunakan panggilan ke fungsi MUI LoadMUILibrary dan FreeMUILibrary.

// Down-Level enabled application that will work with Windows 2000 and later

#include <windows.h>
#include <wchar.h>
#include <strsafe.h>
#include <Nlsdl.h>
#include <MUILoad.h>
#include "resource.h"

#define SUFFICIENTLY_LARGE_STRING_BUFFER (MAX_PATH*2)
#define USER_CONFIGURATION_STRING_BUFFER (((LOCALE_NAME_MAX_LENGTH+1)*5)+1)
#define SUFFICIENTLY_LARGE_ERROR_BUFFER (1024*2)

BOOL GetMyUserDefinedLanguages(WCHAR * langStr, DWORD langStrSize);
BOOL ConvertMyLangStrToMultiLangStr(WCHAR * langStr, WCHAR * langMultiStr, DWORD langMultiStrSize);

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    UNREFERENCED_PARAMETER(hInstance);
    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);
    UNREFERENCED_PARAMETER(nCmdShow);

    // The following code presents a hypothetical, yet common use pattern of MUI technology
    WCHAR displayBuffer[SUFFICIENTLY_LARGE_ERROR_BUFFER];

    // 1. Application starts by applying any user defined language preferences
    // (language setting is potentially optional for an application that wishes to strictly use OS system language fallback)
    // 1a. Application looks in pre-defined location for user preferences (registry, file, web, etc.)
    WCHAR userLanguagesString[USER_CONFIGURATION_STRING_BUFFER*2];
    if(!GetMyUserDefinedLanguages(userLanguagesString,USER_CONFIGURATION_STRING_BUFFER*2))
    {
        swprintf_s(displayBuffer,SUFFICIENTLY_LARGE_ERROR_BUFFER,L"FAILURE: Unable to find the user defined language configuration, last error = %d.",GetLastError());
        MessageBoxW(NULL,displayBuffer,L"HelloMUI ERROR!",MB_OK | MB_ICONERROR);
        return 1; // exit
    }
    // 1b. Application converts the user defined 'readable' languages to the proper multi-string 'less readable' language name format
    WCHAR userLanguagesMultiString[USER_CONFIGURATION_STRING_BUFFER];
    if(!ConvertMyLangStrToMultiLangStr(userLanguagesString,userLanguagesMultiString,USER_CONFIGURATION_STRING_BUFFER))
    {
        swprintf_s(displayBuffer,SUFFICIENTLY_LARGE_ERROR_BUFFER,L"FAILURE: Unable to convert the user defined language configuration to multi-string, last error = %d.",GetLastError());
        MessageBoxW(NULL,displayBuffer,L"HelloMUI ERROR!",MB_OK | MB_ICONERROR);
        return 1; // exit
    }
    // 1c. Application now attempts to set the fallback list - this is much different for a down-level 
    // shipping application when compared to a Vista or Windows 7  only shipping application    
    BOOL setSuccess = FALSE;
    DWORD setLangCount = 0;
    HMODULE hDLL = GetModuleHandleW(L"kernel32.dll");
    if( hDLL )
    {
        typedef BOOL (* SET_PREFERRED_UI_LANGUAGES_PROTOTYPE ) ( DWORD, PCWSTR, PULONG );
        SET_PREFERRED_UI_LANGUAGES_PROTOTYPE fp_SetPreferredUILanguages = (SET_PREFERRED_UI_LANGUAGES_PROTOTYPE)NULL;
        fp_SetPreferredUILanguages = (SET_PREFERRED_UI_LANGUAGES_PROTOTYPE) GetProcAddress(hDLL,"SetProcessPreferredUILanguages");
        if( fp_SetPreferredUILanguages )
        {
            // call SetProcessPreferredUILanguages if it is available in Kernel32.dll's export table - Windows 7 and later
            setSuccess = fp_SetPreferredUILanguages(MUI_LANGUAGE_NAME,userLanguagesMultiString,&setLangCount);
        }
        else
        {
            fp_SetPreferredUILanguages = (SET_PREFERRED_UI_LANGUAGES_PROTOTYPE) GetProcAddress(hDLL,"SetThreadPreferredUILanguages");
            // call SetThreadPreferredUILanguages if it is available in Kernel32.dll's export table - Windows Vista and later
            if(fp_SetPreferredUILanguages)
                setSuccess = fp_SetPreferredUILanguages(MUI_LANGUAGE_NAME,userLanguagesMultiString,&setLangCount);
        }
    }

    // 2. Application obtains access to the proper resource container 
    // for standard Win32 resource loading this is normally a PE module
    // LoadMUILibrary is the preferred alternative for loading of resource modules
    // when the application is potentially run on OS versions prior to Vista
    // LoadMUILibrary is available via Windows SDK releases in Vista and later
    // When available, it is advised to get the most up-to-date Windows SDK (e.g., Windows 7)
    HMODULE resContainer = NULL;
    if(setSuccess) // Vista and later OS scenario
    {
        resContainer = LoadMUILibraryW(HELLO_MODULE_CONTRIVED_FILE_PATH,MUI_LANGUAGE_NAME,0);
    }
    else // this block should only be hit on XP and earlier OS platforms as setSuccess will be TRUE on Vista and later
    {
        // need to provide your own fallback mechanism such as the implementation below
        // in essence the application will iterate through the user configured language list
        WCHAR * next = userLanguagesMultiString;
        while(!resContainer && *next != L'\0')
        {
            // convert the language name to an appropriate LCID
            // DownlevelLocaleNameToLCID is available via standalone download package 
            // and is contained in Nlsdl.h / Nlsdl.lib
            LCID nextLcid = DownlevelLocaleNameToLCID(next,DOWNLEVEL_LOCALE_NAME);
            // then have LoadMUILibrary attempt to probe for the right .mui module
            resContainer = LoadMUILibraryW(HELLO_MODULE_CONTRIVED_FILE_PATH,MUI_LANGUAGE_NAME,(LANGID)nextLcid);
            // increment to the next language name in our list
            size_t nextStrLen = 0;
            if(SUCCEEDED(StringCchLengthW(next,LOCALE_NAME_MAX_LENGTH,&nextStrLen)))
                next += (nextStrLen + 1);
            else
                break; // string is invalid - need to exit
        }
        // if the user configured list did not locate a module then try the languages associated with the system
        if(!resContainer)
            resContainer = LoadMUILibraryW(HELLO_MODULE_CONTRIVED_FILE_PATH,MUI_LANGUAGE_NAME,0);
    }
    if(!resContainer)
    {
        swprintf_s(displayBuffer,SUFFICIENTLY_LARGE_ERROR_BUFFER,L"FAILURE: Unable to load the resource container module, last error = %d.",GetLastError());
        MessageBoxW(NULL,displayBuffer,L"HelloMUI ERROR!",MB_OK | MB_ICONERROR);
        return 1; // exit
    }

    // 3. Application parses the resource container to find the appropriate item
    WCHAR szHello[SUFFICIENTLY_LARGE_STRING_BUFFER];
    if(LoadStringW(resContainer,HELLO_MUI_STR_0,szHello,SUFFICIENTLY_LARGE_STRING_BUFFER) == 0)
    {
        swprintf_s(displayBuffer,SUFFICIENTLY_LARGE_ERROR_BUFFER,L"FAILURE: Unable to load the resource string, last error = %d.",GetLastError());
        MessageBoxW(NULL,displayBuffer,L"HelloMUI ERROR!",MB_OK | MB_ICONERROR);
        FreeLibrary(resContainer);
        return 1; // exit
    }

    // 4. Application presents the discovered resource to the user via UI
    swprintf_s(displayBuffer,SUFFICIENTLY_LARGE_ERROR_BUFFER,L"%s MUI",szHello);
    MessageBoxW(NULL,displayBuffer,L"HelloMUI",MB_OK | MB_ICONINFORMATION);

    // 5. Application cleans up memory associated with the resource container after this item is no longer needed.
    if(!FreeMUILibrary(resContainer))
    {
        swprintf_s(displayBuffer,SUFFICIENTLY_LARGE_ERROR_BUFFER,L"FAILURE: Unable to unload the resource container, last error = %d.",GetLastError());
        MessageBoxW(NULL,displayBuffer,L"HelloMUI ERROR!",MB_OK | MB_ICONERROR);
        return 1; // exit
    }

    return 0;
}

BOOL GetMyUserDefinedLanguages(WCHAR * langStr, DWORD langStrSize)
{
    BOOL rtnVal = FALSE;
    // very simple implementation - assumes that first 'langStrSize' characters of the 
    // L".\\langs.txt" file comprises a string of one or more languages
    HANDLE langConfigFileHandle = CreateFileW(L".\\langs.txt", GENERIC_READ, 0, 
        NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
    if(langConfigFileHandle != INVALID_HANDLE_VALUE)
    {
        // clear out the input variables
        DWORD bytesActuallyRead = 0;
        if(ReadFile(langConfigFileHandle,langStr,langStrSize*sizeof(WCHAR),&bytesActuallyRead,NULL) && bytesActuallyRead > 0)
        {
            rtnVal = TRUE;
            DWORD nullIndex = (bytesActuallyRead/sizeof(WCHAR) < langStrSize) ? bytesActuallyRead/sizeof(WCHAR) : langStrSize;
            langStr[nullIndex] = L'\0';
        }
        CloseHandle(langConfigFileHandle);
    }
    return rtnVal;
}

BOOL ConvertMyLangStrToMultiLangStr(WCHAR * langStr, WCHAR * langMultiStr, DWORD langMultiStrSize)
{
    BOOL rtnVal = FALSE;
    size_t strLen = 0;
    rtnVal = SUCCEEDED(StringCchLengthW(langStr,USER_CONFIGURATION_STRING_BUFFER*2,&strLen));
    if(rtnVal && strLen > 0 && langMultiStr && langMultiStrSize > 0)
    {
        WCHAR * langMultiStrPtr = langMultiStr;
        WCHAR * last = langStr + (langStr[0] == 0xFEFF ? 1 : 0);
        WCHAR * context = last;
        WCHAR * next = wcstok_s(last,L",; :",&context);
        while(next && rtnVal)
        {
            // make sure you validate the user input
            if(SUCCEEDED(StringCchLengthW(last,LOCALE_NAME_MAX_LENGTH,&strLen)) 
                && DownlevelLocaleNameToLCID(next,0) != 0)
            {
                langMultiStrPtr[0] = L'\0';
                rtnVal &= SUCCEEDED(StringCchCatW(langMultiStrPtr,(langMultiStrSize - (langMultiStrPtr - langMultiStr)),next));
                langMultiStrPtr += strLen + 1;
            }
            next = wcstok_s(NULL,L",; :",&context);
            if(next)
                last = next;
        }
        if(rtnVal && (langMultiStrSize - (langMultiStrPtr - langMultiStr))) // make sure there is a double null term for the multi-string 
        {
            langMultiStrPtr[0] = L'\0';
        }
        else // fail and guard anyone whom might use the multi-string
        {
            langMultiStr[0] = L'\0';
            langMultiStr[1] = L'\0';
        }
    }
    return rtnVal;
}