pdfium 代码执行流程

 1.FPDF_InitLibrary(NULL);

CPDF_CustomAccess::CPDF_CustomAccess(FPDF_FILEACCESS* pFileAccess)

{

    if (pFileAccess)

        m_FileAccess = *pFileAccess;

}

 FPDF_LoadCustomDocument

CPDF_CustomAccess* pFil

int first_page = FPDFAvail_GetFirstPageNum(doc);
(void) FPDFAvail_IsPageAvail(pdf_avail, first_page, &hints);

e = FX_NEW CPDF_CustomAccess(pFileAccess);

  int page_count = FPDF_GetPageCount(doc);   //页数统计

  FPDF_DOCUMENT doc;

https://pdfium.patagames.com/help/html/m_patagames_pdf_pdfium_fpdf_loaddocument.htm  api接口说明