API	Source	Windows 95	Windows 98
TextOutW	Win32 API	Yes	Yes
TextOutExW	Win32 API	Yes	Yes
GetCharWidthW	Win32 API	Yes	Yes
GetTextExtentPointW	Win32 API	Yes	Yes
GetTextExtentPoint32W	Win32 API	Yes	Yes
MessageBoxW	Win32 API	Yes	Yes
MessageBoxExW	Win32 API	Yes	Yes
lstrcpyW	Win32 API	No	Yes
lstrcatW	Win32 API	No	Yes
lstrlenW	Win32 API	No	Yes
wcs* functions	CRTL	Yes	Yes
Script* functions	Uniscribe	Yes (except Far East versions)	Yes

Figure 2   A Unicode Wrapper for RegisterClassEx

ATOM WINAPI RegisterClassExAU(CONST WNDCLASSEXW *lpWcw)
{
    WNDCLASSEXA wca                   ;
    CHAR        szClassName[MAX_NAME] ;

    wca.cbSize       = sizeof(WNDCLASSEXA) ;
    wca.cbClsExtra   = lpWcw->cbClsExtra   ;
    wca.cbWndExtra   = lpWcw->cbWndExtra   ;
    wca.hbrBackground= lpWcw->hbrBackground;
    wca.hCursor      = lpWcw->hCursor      ;
    wca.hIcon        = lpWcw->hIcon        ;
    wca.hIconSm      = lpWcw->hIconSm      ;
    wca.hInstance    = lpWcw->hInstance    ;
    wca.lpfnWndProc  = lpWcw->lpfnWndProc  ;
    wca.style        = lpWcw->style        ;

    if(NULL == lpWcw->lpszClassName) {
        return 0 ;
    }
    wca.lpszClassName   = szClassName ;

    if(!WideCharToMultiByte(CP_ACP, 0, lpWcw->lpszClassName, -1, szClassName, 
                            MAX_NAME, NULL, NULL)) {
        return 0 ;
    }

    // Note: This only works if the menu id is a constant rather than a string
    wca.lpszMenuName = (LPSTR) lpWcw->lpszMenuName ; 
    return RegisterClassExA(&wca) ;
}

Figure 3   Message Converter Function

BOOL WINAPI ConvertMessageAU(
    IN   HWND hWnd , IN UINT message , IN OUT  WPARAM *pwParam ,
    IN OUT  LPARAM *plParam)
{
    static CHAR s_sANSIchar[3] = "\0" ;
    int nReturn ;

    switch (message)
    {
    case WM_CHAR:
        // We have to go through all this malarky because DBCS characters 
        // arrive one byte at a time. In this sample application, most of
        // this code is never used because DBCS chars are handled by 	        
	// WM_IME_CHAR below. You can comment out that case 
        // (and the corresponding one in WinProc) to test this code.
        if(!s_sANSIchar[0]) {  // No lead byte already waiting for trail byte
            s_sANSIchar[0] = (CHAR) *pwParam ; 

            if(IsDBCSLeadByteEx(g_InputCodePage , *pwParam)) {
                // This is a lead byte. Save it and wait for trail byte
                return FALSE;
            }
            // Not a DBCS character. Convert to Unicode.
            MultiByteToWideChar(g_InputCodePage , 0, s_sANSIchar, 1, 
                                (LPWSTR) pwParam, 1) ;
            s_sANSIchar[0] = 0 ;    // Reset to indicate no Lead byte waiting
            return TRUE ;
        }
        else { // Have lead byte, pwParam should contain the trail byte
            s_sANSIchar[1] = (CHAR) *pwParam ;
            // Convert both bytes into one Unicode character
            MultiByteToWideChar(g_InputCodePage , 0, s_sANSIchar, 2, 
                                (LPWSTR) pwParam, 1) ;
            s_sANSIchar[0] = 0 ;    // Reset to non-waiting state
            return TRUE ;
        }

    case WM_IME_CHAR:
        // The next 3 lines replace all but one line in the WM_CHAR case above. 
        // This is why it's best to use WM_IME_CHAR rather than WM_CHAR 
        // to get DBCS chars in ANSI mode.
        s_sANSIchar[1] = LOBYTE((WORD) *pwParam) ;
        s_sANSIchar[0] = HIBYTE((WORD) *pwParam) ;
        
        nReturn = MultiByteToWideChar(g_InputCodePage , 0, s_sANSIchar, 2, 
                                      (LPWSTR) pwParam, 1) ;
        return (nReturn > 0) ;

    case WM_INPUTLANGCHANGEREQUEST:
    {
        HKL NewInputLocale = (HKL) *plParam ;

        LANGID wPrimaryLang = 
            PRIMARYLANGID(LANGIDFROMLCID(LOWORD(NewInputLocale))) ;

        // Reject change to Indic keyboards, since they are not supported in 
        // ANSI mode
        switch (wPrimaryLang) {
            case LANG_ASSAMESE :
            case LANG_BENGALI :
            case LANG_GUJARATI :
            case LANG_HINDI :
            // Other Indian scripts omitted
            case LANG_TAMIL :
            case LANG_TELUGU :
                return FALSE ;
        }
        g_InputCodePage = LangToCodePage( LOWORD(NewInputLocale) ) ; 
           // Utility defined below
        return TRUE ;
    }
    default:
        return TRUE ;
    }
}

Figure 4   Handy Windows 2000 Functions

LANGID GetSystemDefaultUILanguage() Returns the LANGID for the system default UI language, or 0 on failure. LANGID GetUserDefaultUILanguage() Returns the LANGID for the current user's UI language, or 0 on failure. BOOL EnumUILanguages( UILANGUAGE_ENUMPROC lpUILanguageEnumProc, // Pointer to enumeration callback function DWORD dwFlags, // Flags -- reserved, must be 0 LPARAM lParam // Parameter to pass to the callback function ) ; Enumerates the UI languages that are available on the system. BOOL IsValidLanguageGroup( LGRPID LanguageGroup, // Language group identifier to validate DWORD dwFlags // specifies validity test ) ; IsValidLanguageGroup returns TRUE or FALSE as follows: if dwFlags is LGRPID_INSTALLED, the return value is TRUE if and only if the language of the language group identifier is both supported and installed; if dwFlags is LGRPID_SUPPORTED, the return value is TRUE if and only if language group identifier is supported. BOOL EnumSystemLanguageGroups( LANGUAGEGROUP_ENUMPROC lpLanguageGroupEnumProc, // Pointer to enumeration callback function DWORD dwFlags, // Language groups to enumerate LPARAM lParam // Parameter to pass to the callback function ) ; Enumerates the language groups that are installed or sup--ported. Set flag LGRPID_INSTALLED or LGRPID_SUPPORTED in dwFlags to specify which to enumerate. BOOL EnumLanguageGroupLocales( // Pointer to Enumeration callback function LANGGROUPLOCALE_ENUMPROC lpLangGroupLocaleEnumProc, LGRPID LanguageGroup, // Language group to evaluate DWORD dwFlags, // Option flags LONG lParam // lParam to pass the Callback function ); Enumerates all the locales supported by a given language group.