NLS: ejemplo de normalización Unicode

La aplicación de ejemplo descrita en este tema muestra la representación de cadenas mediante la normalización Unicode.

La aplicación de ejemplo llama a las cuatro formas de normalización Unicode con la misma cadena de entrada. A continuación, se realiza una llamada con Unicode no válido para mostrar cómo funciona el índice de código de carácter incorrecto. Por último, la aplicación pasa una cadena que se expande para ser anormalmente larga, por lo que requiere varias llamadas de normalización de cadena para obtener un tamaño de búfer adecuado.

Este ejemplo muestra las siguientes funciones de la API NLS:

• IsNormalizedString
• NormalizeString

// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF 
// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO 
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A 
// PARTICULAR PURPOSE. 
// 
// Copyright (c) Microsoft Corporation. All rights reserved. 

// ============ Demonstration of Normalization APIs ============ 

#include "stdafx.h"
#include "windows.h"
#include <stdio.h>
#include <tchar.h>
#include "malloc.h"

// Print out a string using code points for the non-ASCII values 
void DumpString(LPWSTR pInput)
{
    while (*pInput != 0)
    {
        if (*pInput < 0x80)
            wprintf(L"%c", *pInput);
        else
            wprintf(L"\\x%4.4x", *pInput);
        pInput++;
    }
    wprintf(L"\n");
}

// Check if normalized and display normalized output for a particular normalization form 
void TryNormalization(NORM_FORM form, LPWSTR strInput)
{
    // Test if the string is normalized 
    if (IsNormalizedString(form, strInput, -1))
    {
        wprintf(L"Already normalized in this form\n");
    }
    else
    {
        // It was not normalized, so normalize it 
        int    iSizeGuess;
        LPWSTR pBuffer;

        // How big is our buffer (quick guess, usually enough) 
        iSizeGuess = NormalizeString(form, strInput, -1, NULL, 0);

        if (iSizeGuess == 0)
        {
            wprintf(L"Error %d checking for size\n", GetLastError());
        }

        while(iSizeGuess > 0)
        {
            pBuffer = (LPWSTR)malloc(iSizeGuess * sizeof(WCHAR));
            if (pBuffer)
            {
                // Normalize the string 
                int iActualSize = NormalizeString(form, strInput, -1, pBuffer, iSizeGuess);
                iSizeGuess = 0;
                if (iActualSize <= 0 && GetLastError() != ERROR_SUCCESS)
                {
                    // Error during normalization 
                    wprintf(L"Error %d during normalization\n", GetLastError());
                    if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
                    {
                        // If the buffer is too small, try again with a bigger buffer. 
                        wprintf(L"Insufficient buffer, new suggested buffer size %d\n", -iActualSize);
                        iSizeGuess = -iActualSize;
                    }
                    else if (GetLastError() == ERROR_NO_UNICODE_TRANSLATION)
                    {
                        wprintf(L"Invalid Unicode found at input character index %d\n", -iActualSize);
                    }
                }
                else
                {
                    // Display the normalized string 
                    DumpString(pBuffer);
                }

                // Free the buffer 
                free (pBuffer);
            }
            else
            {
                wprintf(L"Error allocating buffer\n");
                iSizeGuess = 0;
            }
        }
    }
}

int __cdecl wmain(int argc, WCHAR* argv[])
{
     // Tèst string ｔｏ nørmälize 
     LPWSTR strInput = L"T\u00e8st string \uFF54\uFF4F n\u00f8rm\u00e4lize";

    wprintf(L"Comparison of Normalization Forms, input string::\n");
    DumpString(strInput);

    // Try it in the 4 forms 
    wprintf(L"\n");
    wprintf(L"String in Form C:\n  ");
    TryNormalization(NormalizationC, strInput);

    wprintf(L"\n");
    wprintf(L"String in Form KC:\n  ");
    TryNormalization(NormalizationKC, strInput);

    wprintf(L"\n");
    wprintf(L"String in Form D:\n  ");
    TryNormalization(NormalizationD, strInput);

    wprintf(L"\n");
    wprintf(L"String in Form KD:\n  ");
    TryNormalization(NormalizationKD, strInput);

    // Note that invalid Unicode would show an error (illegal lone surrogate in this case) 
    wprintf(L"\n");
    wprintf(L"Attempt to normalize illegal lone surrogate:\n");
    TryNormalization(NormalizationC, L"Bad surrogate is here: '\xd800'");

    // Contrived strings can cause the initial size guess to be low 
    wprintf(L"\n");
    wprintf(L"Attempt to normalize a string that expands beyond the initial guess\n");
    TryNormalization(NormalizationC,
        // These all expand to 2 characters 
        L"\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958"
        L"\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958"
        L"\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958"
        L"\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958\u0958"
        // These all expand to 3 characters 
        L"\ufb2c\ufb2c\ufb2c\ufb2c\ufb2c\ufb2c\ufb2c\ufb2c\ufb2c\ufb2c\ufb2c\ufb2c"
        L"\ufb2c\ufb2c\ufb2c\ufb2c\ufb2c\ufb2c\ufb2c\ufb2c\ufb2c\ufb2c\ufb2c\ufb2c");
}