Visual c++ 如何在Silverlight For Windows Embedded中的InkPresenter上书写？

我想在嵌入式设备上做一个涂鸦式的控件，这就是我到目前为止所做的：

放置了InkPresenter控件（Home_Ink），以下是其事件：

Home\u Ink\u MouseLeftButtonDown:

  m_pHome_Ink->CaptureMouse(retValue);
  pApplication->CreateObject(&s);
  pApplication->CreateObject(&pStylusPoints);
  pApplication->CreateObject(&pDrawingAttributes);

  s->SetStylusPoints(pArgs->pStylusPoints);

  pDrawingAttributes->SetHeight(pencilWidth);
  pDrawingAttributes->SetWidth(pencilWidth);
  pDrawingAttributes->SetColor(pencilColor);
  s->SetDrawingAttributes(pDrawingAttributes);

  m_pHome_Ink->GetStrokes(&pStrokes);
  pStrokes->Add(s,NULL);

  s=NULL;
  m_pHome_Ink->ReleaseMouseCapture();

  if(s!=NULL)
  {
        s->SetStylusPoints(pArgs->pStylusPoints);
        pStrokes->Add(s,NULL);
  }

Home\u Ink\u MouseLeftButtonUp:

  m_pHome_Ink->CaptureMouse(retValue);
  pApplication->CreateObject(&s);
  pApplication->CreateObject(&pStylusPoints);
  pApplication->CreateObject(&pDrawingAttributes);

  s->SetStylusPoints(pArgs->pStylusPoints);

  pDrawingAttributes->SetHeight(pencilWidth);
  pDrawingAttributes->SetWidth(pencilWidth);
  pDrawingAttributes->SetColor(pencilColor);
  s->SetDrawingAttributes(pDrawingAttributes);

  m_pHome_Ink->GetStrokes(&pStrokes);
  pStrokes->Add(s,NULL);

  s=NULL;
  m_pHome_Ink->ReleaseMouseCapture();

  if(s!=NULL)
  {
        s->SetStylusPoints(pArgs->pStylusPoints);
        pStrokes->Add(s,NULL);
  }

主页\u墨水\u鼠标移动：

  m_pHome_Ink->CaptureMouse(retValue);
  pApplication->CreateObject(&s);
  pApplication->CreateObject(&pStylusPoints);
  pApplication->CreateObject(&pDrawingAttributes);

  s->SetStylusPoints(pArgs->pStylusPoints);

  pDrawingAttributes->SetHeight(pencilWidth);
  pDrawingAttributes->SetWidth(pencilWidth);
  pDrawingAttributes->SetColor(pencilColor);
  s->SetDrawingAttributes(pDrawingAttributes);

  m_pHome_Ink->GetStrokes(&pStrokes);
  pStrokes->Add(s,NULL);

  s=NULL;
  m_pHome_Ink->ReleaseMouseCapture();

  if(s!=NULL)
  {
        s->SetStylusPoints(pArgs->pStylusPoints);
        pStrokes->Add(s,NULL);
  }

没有生成错误，应用程序正在运行。 但是没有任何东西被inkpresenter吸引。我做错了什么