VC+AE制作鹰眼图问题！

<P>本人今天写了一段用AE+VC的鹰眼图程序，但是总是在一条语句那出问题，请大虾指导下，谢谢。</P>
<P>前面部分的代码如下：（在mapcontrol的OnExtentUpdatedMapctrl消息中）</P>
<P> IEnvelopePtr ipEnvelope;<BR> IGraphicsContainerPtr ipGraph;<BR> IActiveViewPtr ipActiveView;</P>
<P> HRESULT hr=m_ipMapControl2->get_ActiveView(;ipActiveView);<BR> if(FAILED(hr)) return;<BR> ipGraph=ipActiveView;<BR> hr=ipGraph->DeleteAllElements();<BR> if(FAILED(hr)) return;</P>
<P> IElementPtr ipElement(CLSID_RectangleElement);<BR> IRectangleElementPtr ipRectElement;<BR> ipElement=ipRectElement;<BR> IGeometryPtr ipGeometry;<BR> hr=m_ipMapControl->get_Extent(;ipEnvelope);<BR> if(FAILED(hr)) return;<BR>  ipGeometry=ipEnvelope.GetInterfacePtr();<BR> hr=ipElement->put_Geometry(ipGeometry);<BR> if(FAILED(hr)) return;</P>
<P>总是在hr=ipElement->put_Geometry(ipGeometry);这出错，不知道为什么？该怎么写呢？<BR></P>

<P>刚刚看一本COM书的时候得到灵感了，问题解决。但是本着造福大家的思想，我把我写好通过的代码贴给大家。</P>
<P>void CAlgoTestView::OnExtentUpdatedMapctrl(const VARIANT FAR; displayTransformation, BOOL sizeChanged, const VARIANT FAR; newEnvelope) <BR>{<BR> IEnvelopePtr ipEnvelope;<BR> IGraphicsContainerPtr ipGraph;<BR> IActiveViewPtr ipActiveView;<BR> IMapPtr ipMap;</P>
<P> HRESULT hr=m_ipMapControl2->get_ActiveView(;ipActiveView);<BR> if(FAILED(hr)) return;<BR> ipGraph=ipActiveView;<BR> hr=ipGraph->DeleteAllElements();<BR> if(FAILED(hr)) return;</P>
<P> IElementPtr ipElement;<BR> IRectangleElementPtr ipRectElement(CLSID_RectangleElement);//相当于vb中的ipRectElement= new RectangleElement<BR> ipElement=ipRectElement;<BR> IGeometryPtr ipGeometry;<BR> hr=m_ipMapControl->get_Extent(;ipEnvelope);<BR> if(FAILED(hr)) return;<BR>  ipGeometry=ipEnvelope.GetInterfacePtr();<BR> hr=ipElement->put_Geometry(ipGeometry);<BR> if(FAILED(hr)) return;</P>
<P> IRgbColorPtr ipRgbColor(CLSID_RgbColor);<BR> ipRgbColor->put_RGB(RGB(255,0,0));<BR> ipRgbColor->put_Transparency(255);</P>
<P> ILineSymbolPtr ipLineSymbol(CLSID_SimpleLineSymbol);//相当于vb中的ipLineSymbol= new SimpleLineSymbol<BR> ipLineSymbol->put_Width(1);<BR> ipLineSymbol->put_Color(ipRgbColor);</P>
<P> ipRgbColor->put_RGB(RGB(255,0,0));<BR> ipRgbColor->put_Transparency(0);</P>
<P> IFillSymbolPtr ipFillSymbol(CLSID_SimpleFillSymbol);<BR> ipFillSymbol->put_Color(ipRgbColor);<BR> ipFillSymbol->put_Outline(ipLineSymbol);</P>
<P> IFillShapeElementPtr ipFillShapeElement;<BR> ipFillShapeElement=ipElement;<BR> ipFillShapeElement->put_Symbol(ipFillSymbol);<BR> ipGraph->AddElement(ipElement,0);<BR> ipActiveView->Refresh();<BR> <BR>}</P>
<P>虽然还不是十分完美，但是基本的功能已经实现了。</P>

<P>加上下面两段就可以实现鹰眼控件和主控件的联动。</P>
<P>void CAlgoTestView::OnMouseDownMapctrl2(long button, long shift, long X, long Y, double mapX, double mapY) <BR>{<BR> if (2==button)<BR> {<BR>  IPointPtr ipPoint(CLSID_Point);<BR>  IMapPtr ipMap;<BR>  ipPoint->put_X(mapX);<BR>  ipPoint->put_Y(mapY);</P>
<P>  IEnvelopePtr ipEnvelope;<BR>  m_ipMapControl2->TrackRectangle(;ipEnvelope);<BR>  m_ipMapControl->put_Extent(ipEnvelope);<BR> }<BR>}</P>
<P>void CAlgoTestView::OnMouseMoveMapctrl2(long button, long shift, long X, long Y, double mapX, double mapY) <BR>{<BR> if (1==button)<BR> {<BR>  IPointPtr ipPoint(CLSID_Point);<BR>  IMapPtr ipMap;<BR>  ipPoint->put_X(mapX);<BR>  ipPoint->put_Y(mapY);<BR>  <BR>  IEnvelopePtr ipEnvelope;<BR>  m_ipMapControl->get_Extent(;ipEnvelope);<BR>  ipEnvelope->CenterAt(ipPoint);<BR>  m_ipMapControl->put_Extent(ipEnvelope);<BR>  <BR> }<BR>}</P>

<P>更加简单的实现</P>
<P>procedure TFrmMain.MapMainAfterDraw(ASender: TObject; Display: OleVariant;<BR>  viewDrawPhase: Integer);<BR>var<BR>  FillSymbol: IFillSymbol;<BR>  pColor: IColor;<BR>  outline: ILineSymbol;<BR>  flag: WordBool;<BR>  symbol: OleVariant;<BR>begin<BR>  //红框<BR>  pColor:=CoRgbColor.create as IColor;<BR>  outline:= CoSimpleLineSymbol.create as ILineSymbol;<BR>  pColor.Set_RGB(RGB(255, 0, 0));<BR>  pColor.Set_Transparency(255);<BR>  outline.Set_Color(pColor);<BR>  outline.Set_Width(1.5);</P>
<P>  //填充<BR>  pColor:=CoRgbColor.create as IColor;<BR>  pColor.Set_RGB(RGB(0,0,0));<BR>  pColor.Set_Transparency(0);<BR>  FillSymbol:=CoSimpleFillSymbol.create as IFillSymbol;<BR>  FillSymbol.Set_Color(pColor);<BR>  FillSymbol.Set_Outline(outline);</P>
<P>  //画鹰眼<BR>  MapEye.Refresh;<BR>  symbol:=FillSymbol;<BR>  MapEye.DrawShape(mapMain.Extent,symbol);<BR>end;</P>

<P>这样的帖子怎么没人支持啊！</P>

<P>这个程序，应该是针对对话框的吧，如果要是用单文档来做，恐怕非常麻烦了，不知道楼主是否做过啊？</P>