Delphi XE10, DigitalPersona Fingerprint reader and MySQL

Hi,

I was wondering if someone might be able to assist me. I have Delphi XE10 and MySQL using a DigitalPersona U.Are.U 4500 fingerprint reader.

I am able to enroll my user and save the fingerprint to a MySQL database but I am unable to verify the user from the database.

This is my code that I have at the moment for verifying the fingerprint.

procedure TMainForm.FPCapture2Complete(ASender: TObject;
  const ReaderSerNum: WideString; const pSample: IDispatch);
  var
    l_interface : IDispatch;
    tptStream : TMemoryStream;
    p : Pointer;
begin
  l_interface := FPGetImage.ConvertToPicture(pSample);
  SetOlePicture(pbPrint2.Picture,IPictureDisp(l_interface));  //display print

  //Search FP in db
  With DM.VerifyQry do
  begin
    Close;
    SQL.Clear;
    SQL.Add('SELECT MemberName, MemberFP FROM MemberTbl');
//    Open;
    Active := True;
    First;
    while (NOT DM.VerifyQry.Eof) do
    begin
      try
       // DM.VerifyQry.Locate('MemberID',FieldByName('MemberID').AsInteger,[]);
        tptStream  := TMemoryStream.Create();
//        (DM.VerifyQry.FieldByName('MemberFP') AS TBlobField).SaveToStream(tptStream);
        TBlobField(DM.VerifyQry.FieldByName('MemberFP')).SaveToStream(tptStream);
        vrnt2   := VarArrayCreate([0, tptStream.Size], VarByte);
        tptStream.Position := 0;
        p := VarArrayLock(vrnt2);
        tptStream.Read(p^, tptStream.Size);
        VarArrayUnlock(vrnt2);
        tptStream.Free;
      except
        tptStream.Free;
        vrnt2:=null;
      end;
      Next;
    end;
  end;

    FPTemplateFromDB2.Deserialize(vrnt2);
    try
      FPExtraction.CreateFeatureSet(pSample,DataPurposeVerification);
    except
      on E: exception do begin
        showmessage('Exception occurred in CreateFeatureSet:' + e.Message);
        exit;
      end;
    end;
    if FPExtraction.FeatureSet=nil then begin
      showmessage('Failed to extract verification features');
      exit;
    end;
    try
      FPVerifyRslt:= FPVerify.Verify(FPExtraction.FeatureSet,FPTemplateFromDB) as DPFPEngXLib_TLB.DPFPVerificationResult;
    except
      on E: Exception do begin
        showmessage('Verify method failed');
        showmessage(e.Message);
        exit;
      end;
    end;

    if fpverifyrslt.Verified=true then begin
      ShowMessage('Matched');
    end else begin
      ShowMessage('Not Verified');
    end;


end;

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And this is my code for saving the fingerprint to the database

procedure TMainForm.FPCaptureComplete(ASender: TObject;
  const ReaderSerNum: WideString; const pSample: IDispatch);
begin
   l_interface := FPGetImage.ConvertToPicture(pSample);
   lblInfo.Caption:='Sample Captured';
   SetOlePicture(pbPrint.Picture,IPictureDisp(l_interface));  //display print
   if breginprogress=true then begin
    if index > 4 then index:=1;     //reset index if beyond 4 presses

    if index=1 then
    begin
    FPImage1.Picture.LoadFromFile(ExtractFilePath(Application.ExeName)+'\images\greenfp.bmp');
    lbl1.Font.Color:=clGreen;
    lbl2.Font.Color:=clYellow;
     end;

    if index=2 then
    begin
    FPImage2.Picture.LoadFromFile(ExtractFilePath(Application.ExeName)+'\images\greenfp.bmp');
    lbl2.Font.Color:=clGreen;
    lbl3.Font.Color:=clYellow;
     end;

   if index=3 then
    begin
    FPImage3.Picture.LoadFromFile(ExtractFilePath(Application.ExeName)+'\images\greenfp.bmp');
    lbl3.Font.Color:=clGreen;
    lbl4.Font.Color:=clYellow;
    end;

    if index=4 then lbl4.Font.Color:=clGreen;

    index := index + 1;

    //Create registration\enrollment featureset from sample captured
           try
    FPExtraction.CreateFeatureSet(pSample,DataPurposeEnrollment);
           except
                on E: Exception do  begin
                showmessage('Exception inside CreateFeatureSet');
                showmessage(E.Message);
                FPregister.Clear;
                ResetLabels;
                index:=1;
                exit;
                 end;

           end;
    if FPExtraction.FeatureSet <> nil then
    //Add features to registration object
     FPRegister.AddFeatures(FPExtraction.FeatureSet)
     else begin
     Showmessage('Could not create featureset, poor press');
     FPRegister.Clear;
     ResetLabels;
     index:=1;
     exit;  //return
     end;
     //If 4 successful features added, status should be 'Ready'
    if FPRegister.TemplateStatus=TemplateStatusTemplateReady then  begin
        FPImage4.Picture.LoadFromFile(ExtractFilePath(Application.ExeName)+'\images\greenfp.bmp');
        lblResult.Caption:='User Enrolled - Press Finger for Verification';
        lbl1.Visible:=false; lbl2.Visible:=false; lbl3.Visible:=false; lbl4.Visible:=false;
        FPTemplate:=FPRegister.Template as DPFPShrXLib_TLB.DPFPTemplate;
        breginprogress:=false;  //stop registration process, enable verification

        //Before saving data to database you will need to get the raw data (variant)
        try
        vrnt:=FPTemplate.Serialize;  //raw data is now stored in this variant

        //Now that you have the variant, try to get raw byte array
        //We are assuming here that you cannot save a variant directly to database field
        //That you need a byte array before saving the data to the database.
        aryLow:=VarArrayLowBound(vrnt,1);
        aryHigh:=varArrayHighBound(vrnt,1);
        aryHigh:=aryHigh-aryLow;

        vtByteBuf:=VarArrayLock(vrnt);  //lock down the array

        for loopIndex := 0 to aryHigh - 1 do
               fpData[loopIndex]:=vtByteBuf[loopIndex];

        VarArrayUnlock(vrnt);

        With DM.MemberTbl do
        begin
          Insert;
          DM.MemberTbl.FieldByName('MemberName').AsString := tmpMemberName;
          DM.MemberTbl.FieldByName('MemberFP').AsVariant := vrnt;
          Post;
        end;


        except
        on E: Exception do showmessage('Trouble saving data');

        end;

        //This section would be in a different form or part of your application.
        //So just pretend that the user is at a login screen

        //Before verification or user login you will need to read the user's fingerprint template from database

         {Database logic not included}

        //Once you get the raw data (here we are just reusing the fpData as opposed
        //To actually loading it from a database) you will need to create a variant array.

         rawDataSize:=High(fpData) - Low(fpData); //Obviously this would be set to actual data length of the field
         try
         vrnt := VarArrayCreate([0,rawDataSize],varByte); //Allocate the array required to store the fpdata in your variant
         vtByteBuf:=VarArrayLock(vrnt);

         for loopIndex := 0 to rawDataSize - 1 do
               vtByteBuf[loopIndex]:=fpData[loopIndex];

         VarArrayUnlock(vrnt);
         except
         on E: Exception do begin
         showmessage('Ole exception');
         showmessage(e.Message);
         FPregister.Clear;    //Reset registration rather than just exit program
                ResetLabels;
                index:=1;
                exit;
         end;
         end;
        //Then recreate a DPFPTemplate object by just calling Deserialize(yourvariant)
        FPTemplateFromDB.Deserialize(vrnt);

        //Now the template (FPTemplate2) is ready to be matched against.
    end
       else if FPRegister.TemplateStatus=TemplateStatusCreationFailed then
       begin
          showmessage('Registration failed');
          FPRegister.Clear;  //Reset registration operation
          ResetLabels();
          index:=1;
          exit;
       end;
   end
   else begin  //Code for verification

   //Create verification featureset
   try
      FPExtraction.CreateFeatureSet(pSample,DataPurposeVerification);
      except
      on E: exception do begin
        showmessage('Exception occurred in CreateFeatureSet:' + e.Message);
        //saveSample('pSample' + IntToStr(fileIndex),DPFPShrXLib_TLB.DPFPSample(pSample));
        fileIndex:= fileIndex+1;
        exit;
       end;

      end;
      if FPExtraction.FeatureSet=nil then
      begin
        showmessage('Failed to extract verification features');
        exit;
      end;
          //Perform verification\matching

          try

      FPVerifyRslt:= FPVerify.Verify(FPExtraction.FeatureSet,FPTemplateFromDB) as DPFPEngXLib_TLB.DPFPVerificationResult;
      except
      on E: Exception do begin
        showmessage('Verify method failed');
        showmessage(e.Message);
        exit;
      end;
          end;
       lblResult.Font.Size:=24;
       if fpverifyrslt.Verified=true then
       begin
        lblResult.Font.Color:=clgreen;
        lblResult.Caption:='Matched!';
       end
       else begin
        lblResult.Font.Color:=clRed;
        lblResult.Caption:='Not matched!';
       end;
   end;
end;

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