FPDFAnnot_SetStringValue Problems encountered

[Wilson Wade]

Hi, I try to add notes to the pdf file, But I ran into some problems, This string runs normally on Foxit Reader, but it displays garbled characters on other PDF readers. For example, Chrome.

Below is my code:

    PDFDocument *pdfDocument = createNewPDFDocument();

    PDFPage *pdfPage = createNewPDFPage(pdfDocument, 0, 800, 1200);

    FPDF_ANNOTATION fpdfAnnotation = FPDFPage_CreateAnnot(pdfPage->fpdfPage, FPDF_ANNOT_TEXT);

    FS_RECTF rect;

    rect.left = 35;

    rect.bottom = 150;

    rect.right = 53;

    rect.top = 165;

    FPDFAnnot_SetRect(fpdfAnnotation, &rect);

    wstring wstring1 = L"XY書き込む文字列";

    FPDFAnnot_SetStringValue(fpdfAnnotation, "Contents", wstringToFPDF_WIDESTRING(wstring1));

    FPDFPage_GenerateContent(pdfPage->fpdfPage);

    savePDFDocumentToFile(pdfDocument, fd);

    closePDFDocument(pdfDocument);

FPDF_WIDESTRING wstringToFPDF_WIDESTRING(std::wstring &wstr) {

    size_t length = sizeof(uint16_t) * (wstr.length() + 1);

    auto *result(static_cast<unsigned short *>(malloc(length)));

    auto *result_span = reinterpret_cast<uint8_t *>(result);

    size_t i = 0;

    for (wchar_t w : wstr) {

        result_span[i++] = w & 0xff;

        result_span[i++] = (w >> 8) & 0xff;

    }

    result_span[i++] = 0;

    result_span[i] = 0;

    return result;

}

Any help is much appreciated.