【vb+ao】怎么合并特征呀？

<P>我在控件mapcontrol1中加入了一幅图片，并选择了图片中的几个多边形，我想合并他们,帮忙改一下代码吧，再给个代码也行。kisssy斑竹你不是发过一个删除多边形的贴吗？合并多边形因改差不多吧。要交毕业设计了 ，大哥们拉兄弟一把，不然我就完了。
Private Sub 合并_Click()</P>
<P>Dim pFeatureSelection As IFeatureSelection
Set pFeatureSelection = MapControl1.Layer(0)
Dim pSelectionSet As ISelectionSet
Set pSelectionSet = pFeatureSelection.SelectionSet</P>
<P>Dim pFeatureCursor As IFeatureCursor
pSelectionSet.Search Nothing, ture, pFeatureCursor</P>
<P>Dim pFeature1 As IFeature, pFeature2 As IFeature
Dim pTopo As ITopologicalOperator
Dim pGeometry As IGeometry</P>
<P>Set pFeature1 = pFeatureCursor.NextFeature
Set pGeometry = pFeature1.Shape
Set pFeature2 = pFeatureCursor.NextFeature
While Not pFeature2 Is Nothing
Set pTopo = pGeometry
Set pGeometry = pTopo.Union(pFeature2.Shape)
Set pFeature2 = pFeatureCursor.NextFeature
Wend</P>
<P>End Sub</P>

<P>我也是想了好长时间，因为帮助中没有关于这个的，所以我也只有一个思路，供你参考：</P><P>按照你上面的代码来，Union之后：</P><P>1，你把pFeatureSelection.SelectionSet的Feature，全部Delete；</P><P>2，然后再用pFeatureCursor  ，Insertfeature（这个Feature，就是你合并的那个：Feature.Shape＝pGeometry）</P><P>Sorry，没有代码</P>