在AO中怎么可以裁剪图层?

请教大家,现有一个图层和一个范围(extent),怎么可以用这个范围来裁剪图层,谢谢,

<P>顶~</P>

<P>同样是在arcscripts.esri.com 找的一个例子,估计也是国人的.我没看,</P><P>Summary  
Function: Clip all layers in current window with the first layer.
Purpose: When you want to clip many layers with the same clip layer at one time. For instance, you want to extract data of your county from many state shape files. Then you may add your county boundary file as first layer and all other state files. Use this tool to clip them all at once.
</P><P>Author: Lihe Wang</P><P>download url:</P><P>hxxp://arcscripts.esri.com/data/AS13040.zip</P>

<P><b>Clip the features of a layer</b></P><P><b>这个例子也可以看下．</b></P>

<P>Sub ClipMapWithGraphic()
    Dim pMxDocument As IMxDocument
   Dim pMap As IMap  
  Dim pViewManager As IViewManager  
  Dim pEnumElement As IEnumElement  
  Dim pElement As IElement  
  Dim pActiveView As IActiveView  
  Dim pBorder As IBorder      
  Set pMxDocument = Application.Document  
  Set pMap = pMxDocument.FocusMap  
     Set pViewManager = pMap 'QI  
  Set pEnumElement = pViewManager.ElementSelection  
  pEnumElement.Reset  
 Set pElement = pEnumElement.Next  
  If pElement Is Nothing Then    
    MsgBox "No element selected"
       Exit Sub  
 End If  
 If pElement.Geometry.GeometryType = esriGeometryPolygon Then    
   Set pBorder = New SymbolBorder 'Use default line symbol  
      pMap.ClipGeometry = pElement.Geometry      
  pMap.ClipBorder = pBorder
        Set pActiveView = pMap    
    pActiveView.Refresh  
  End If
End Sub</P><P>使用mapcontrol的话 可以借鉴一下．</P><P>这部份代码相应改一下</P><P>Set pMxDocument = Application.Document  
  Set pMap = pMxDocument.FocusMap  
这个只是显示上有剪载效果，哈．．</P>

<P>以前看到一个叠加分析的例子,通过两个多边形图层来完成图层的求加,求减,求补操作,我想可以把一个范围保存成一个多边形图层,然后用这个多边形图层减另外一个图层.</P><P>试一下.</P>