VB通过com方式传递数组给c++ 使用VARIANT变量

STDMETHODIMP CMXRender::FillPolygon(VARIANT pts,LONG* res)
{
 // TODO: 在此添加实现代码
 if(pts.vt != (VT_ARRAY|VT_DISPATCH) ||m_GeoRender == NULL)
  return S_FALSE;
 LPSAFEARRAY parr = pts.parray;
 LONG count = 0;
 if(SafeArrayGetDim(parr) == 1 &&SafeArrayGetUBound(parr, 1, &count) == S_OK)
 {
  PointF *points = new PointF[count];
  if(points == NULL)
   return S_FALSE;
  for(LONG i = 0; i < count; i++)
  {
   void *fs = NULL;
   if(SafeArrayGetElement(parr, &i,static_cast<void *>(&fs))!=S_OK)
    return S_FALSE;
   IDispatch *ifs= (IDispatch *)fs;
   CMXPixel* out ;
   HRESULT hr = ifs->QueryInterface(IID_IMXPixel,(void**)&out);
   if (SUCCEEDED(hr))
   {
    points[i].X = out->m_point.x;
    points[i].Y = out->m_point.y;
   }

  }
  *res = m_GeoRender->FillPolygon(points,count);
  delete []points;
 }
 return S_OK;
}

用于转换的部分已经用红色标出

下边的QueryInterface是用来判断传进来的IDispatch 是不是包含我所需要的接口因为强制转换不同的IDispatch 肯定会报错