Not working across managed code - PDPageDrawContentsToWindow - HDC

Question

PageDLL - a Com Dll contains the following:
struct GRect_tag
    long lLeft;
    long lBottom;
    long lTop;
    long lRight;
    }  GRect;
BOOL CMyDrawMC::SetDrawPageToWindow(int hdc, GRect WinRect)
PDDoc objPDDoc;
PDPage objPDPage;
objPDDoc = PDDocOpen("D:\temp\firstfile.pdf", objASFileSys, NULL, true);
objPDPage = PDDocAcquirePage(objPDDoc, 2);
ASFixedMatrix matrix;
ASFixedRect WindowRect;
WindowRect.left    = WinRect.lLeft;
WindowRect.right   = WinRect.lRight;
WindowRect.top     = WinRect.lTop;
WindowRect.bottom  = WinRect.lBottom;
PDPageGetFlippedMatrix(objPDPage, &matrix);
PDPageDrawContentsToWindow(objPDPage, NULL, (void*) hdc, FALSE,
  &matrix,
  &WindowRect, NULL, NULL);
return TRUE;
Managed code written in C# has the following:
protected IntPtr DrawToOffScreenWnd(IntPtr hWnd, int iMsg, IntPtr wParam,
            IntPtr lParam, ref bool bHandled)
            bHandled = false;
            switch (iMsg)
                case WM_PAINT:
                    if (_cobj.GetTotalPagesInDoc() >= 1)
                        // Use Win32 to get a Graphics object.
                        PAINTSTRUCT objPaintStruct = new PAINTSTRUCT();
                        IntPtr hSrcDC = BeginPaint(hWnd, ref objPaintStruct);
                         DrawPage(hwnd, hsrcDC);
                        EndPaint(hWnd, ref objPaintStruct);
                        bHandled = true;
                    break;
            return IntPtr.Zero;
Class MainPanel
public void DrawPage((IntPtr hWnd, IntPtr hSrcDC)
  GRect objWindowRect;
  IntPtr memDC = CreateCompatibleDC(hSrcDC);
  IntPtr memBM = CreateCompatibleBitmap(memDC, objWindowRect.right, objWindowRect.bottom); /* objWindowRect.right is width and objWindowRect.bottom is height values */
  SelectObject(memDC, memBM);
  PageDLL.SetDrawPageToWindow(memDC.ToInt32(), objWindowRect); /* PageDLL is the COM DLL stated in start of this discussion */
  const int SRCCOPY = 13369376;
  bool x = BitBlt(hSrcDC, 0, 0, objWindowRect.right, objWindowRect.bottom, memDC, 0, 0, SRCCOPY);
Question: The window is not getting refreshed with the Page Content of the PDF file.  So, whether the HDC can be passed from Managed code (C#) to Un-managed code (VC++ COM DLL) and return back the HDC content (including HBITMAP of the HDC) to the window created in C#?

Answer 1

thanks for reply.
Jdeveloper version is 11.1.1.4.0.
Actually the vo on which I am trying to set set where is used as source to act as cursor  to get values from filtered rows using set where and copy the this cursor values to another target vo. I am not showing these source values just getting values.
DCIteratorBinding dcIter2 =
ADFUtils.findIterator("PlotDtl2Iterator");     
ViewObject dvo = dcIter2.getViewObject();
// colors to copy 
DCIteratorBinding dcIter3 =
ADFUtils.findIterator("PlanColorsIterator");    
ViewObject cvo = dcIter3.getViewObject();
cvo.setNamedWhereClauseParam("Plno","4000");
cvo.applyViewCriteria(cvo.getViewCriteriaManager().getViewCriteria("PlanColorsCriteria"));
cvo.ensureVariableManager().setVariableValue("Plno", "4000");
cvo.executeQuery();
cvo.setWhereClause("plan_no = :ThePlanType");
cvo.defineNamedWhereClauseParam("ThePlanType", null, null);
cvo.setNamedWhereClauseParam("ThePlanType", "4000");
cvo.executeQuery();
int totalCount=cvo.getRowCount();
cvo.setRangeSize(totalCount);
Row[] rArray=cvo.getAllRowsInRange();
for (Row r:rArray){
NameValuePairs nvp = new NameValuePairs();      
nvp.setAttribute("Description",r.getAttribute("Description"));
nvp.setAttribute("PlanNo",r.getAttribute("PlanNo"));
nvp.setAttribute("MainAcc",r.getAttribute("MainAcc"));
nvp.setAttribute("Plqty",r.getAttribute("Qty"));
nvp.setAttribute("Cdkid",r.getAttribute("CdkId"));
nvp.setAttribute("FabricCode",r.getAttribute("FabricCode"));
nvp.setAttribute("DyeWash",r.getAttribute("DyeWash"));
//  nvp.setAttribute("Description","test");
Row drow = dvo.createAndInitRow(nvp);      
dvo.insertRow(drow);