My work.

Hope that it can help you.

The Function is as follows:

vector CreateBuffer(CMoRecordset; BufferRecords, double; BufferTolerance, int; BufferLayerStyle, string; BufferUnits) { vector TempVectorPoly; CComVariant Extent(m_map.GetFullExtent().m_lpDispatch); if (BufferUnits == "千米")   BufferTolerance = 1000 * BufferTolerance;    switch (BufferLayerStyle) { case 0://点图层   {    BufferRecords.MoveFirst();    while (!BufferRecords.GetEof())    {     CMoPoint point(BufferRecords.GetFields().Item(CComVariant("Shape")).GetValue().pdispVal);     CMoPolygon PolygonBuffer(point.Buffer(BufferTolerance,Extent));     TempVectorPoly.push_back(PolygonBuffer);     BufferRecords.MoveNext();    }    break;   } case 1://线图层   {    BufferRecords.MoveFirst();    while (!BufferRecords.GetEof())    {     CMoLine line(BufferRecords.GetFields().Item(CComVariant("Shape")).GetValue().pdispVal);     CMoPolygon PolygonBuffer(line.Buffer(BufferTolerance,Extent));     TempVectorPoly.push_back(PolygonBuffer);     BufferRecords.MoveNext();      }    break;   } case 2://面图层   {    BufferRecords.MoveFirst();    while (!BufferRecords.GetEof())    {     CMoPolygon Polygon(BufferRecords.GetFields().Item(CComVariant("Shape")).GetValue().pdispVal);     CMoPolygon PolygonBuffer(Polygon.Buffer(BufferTolerance,Extent));     TempVectorPoly.push_back(PolygonBuffer);     BufferRecords.MoveNext();      }    break;   } } return TempVectorPoly; }

不用CComVariant用COleVariant不行吗？

我用CComVariant为什么说未定义？

俺还是个初学者，请多指教！先行谢过

我的代码是这样写的

CMoLine l; CMoLine g_searchLine; l=m_Map.TrackLine(); if(LPDISPATCH(l))  g_searchLine = l;

CMoPolygon shpBuffer; VARIANT va; VariantInit(;va); va.vt=VT_DISPATCH; va.pdispVal=g_searchLine.GetExtent().m_lpDispatch; shpBuffer=g_searchLine.Buffer(100,va);

为什么执行到最后一句shpBuffer=g_searchLine.Buffer(100,va);总是出错？还请多多指教

#include

then you can use CComVariant

you can see MSDN , to search CComVairant ,then you will find:

class CComVariant : public tagVARIANT

i can't find the error if you give me only these codes. but i think maybe the reason is you haven't create the shpBuffer using the "CreateDispatch" mothed. i am not sure. suggest you have a try .

and variant is also ok ,but i haven't used it ,i have no time to try. you can do it by yourself. or ask somebody who have used it .

besides , i strongly suggest that you should use the standard C++ ,use CComVariant .

先谢谢袁兄

其实相关的代码只有我贴出的这些。

我开始用的是COleVariant

先在CMoPolygon shpBuffer;后加入shpBuffer.CreateDispatch(TEXT("MapObjects2.Polygon"));

还是在shpBuffer=g_searchLine.Buffer(100,va);句出错，运行错误提示如下

Unhandled exception in map.exe(OLEAUT32.DLL):OxC000000 Access Violation

后又打算用CComVariant

结果在#include 后编译时提示我fatal error C1083: Cannot open include file: 'atlcomcli.h': No such file or directory

我改成#include "atlcomcli.h"也不行

真是愁人啊，还请列位高人多多指教！

搞定了，我用的是#include

再次多谢袁兄

我想问一下其中的CMoRecordset; BufferRecords是怎么获取的,是对选中的目标进行获取的还是直接对一层数据进行buffer分析的?谢谢!我获取buffer总是空值.