怎么用vc++实现对pdf文档关键字的搜索

CAcroApp *pAcroApp = new CAcroApp;
COleException e;
pAcroApp->CreateDispatch("AcroExch.App", &e);
pAcroApp->Show();    

CAcroAVDoc *pAvdoc= new CAcroAVDoc;
pAvdoc->CreateDispatch("AcroExch.AVDoc", &e);
if(!pAvdoc->Open("c:\\test.pdf", NULL)) 
AfxMessageBox("Error in opening a PDF file.");

// set parameters
BOOL bCaseSensitive = false, bWholeWordsOnly=true, bReset= true;
BOOL rc = pAvdoc->FindText("text", bCaseSensitive, bWholeWordsOnly, bReset);
if(!rc)
AfxMessageBox("Cannot find the text in the document.");

pAcroApp->CloseAllDocs();
pAcroApp->Hide();
pAcroApp->Exit();

// clean memory
delete pAcroApp;
pAcroApp = NULL;    
delete pAvdoc;
pAvdoc = NULL;