2008-07-09 11:57 | 只看楼主
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AE创建泰森多边形

ArcEngin提供了TIN组件,可以利用等高线或离散的高程值生成TIN的方法,其实等高线和离散点都可以看作是要素类—feature class
AE的组件TIN提供了一个非常重要的接口ITinEdit利用这个接口,可以方便地生成三维的TIN,
思路:1找到一个数据集,作为生成TIN的数据源,我们用shp文件来做,它必须有一个字段里含用高程值,2.利用ITinEdit接口生成TIN
重要的是这两个方法:InitNew(int pExtent,,IEnvelope)它需要一个IEnvelope接口的对象
以及方法:SetSpatialReference(int pSpatialReference,ISPatialReference);因此我们首先创建一个ISpatialReference接口对象,利用get_SpatialReference属性得到要素类的空间引用并将空间引用赋给ISpatialReference接口对象,再创建一个IEnvelope接口对象,利用putref_ SpatialReference属性将前面创建的ISpatialReference接口对象的空间引用赋给IEnvelope接口对象,再创建一个TIN对象并得到其ITinEdit接口,利用此接口的InitNew方法创建TIN,而前面创建的IEnvelope接口对象作为该方法的输入对象,这样就可以生成TIN了.
3.上面已能生成TIN,但生成的TIN并没有高程信息,要获得高程字段,再生成三维TIN,这要用到IFields接口和IField的指针,用其get_Fields方法获取高程信息.

代码如下:
//创建TIN数据,同时根据以有的要素类来创建泰森多边形


Public Sub CreateTin()
  Dim TinSu{MOD}ce As ITin
  Set TinSu{MOD}ce = New Tin
  Dim FeatClass As IFeatureClass
  Dim Pdocment As IMxDocument
  Set Pdocment = ThisDocument
  Dim pFeatureLayer As IFeatureLayer
  Set pFeatureLayer = Pdocment.ActiveView.FocusMap.Layer(0)
 
  Dim pEnv As IEnvelope
  Set pEnv = pFeatureLayer.AreaOfInterest.Envelope
 
  Dim pTinEdit As ITinEdit
  Set pTinEdit = New Tin
  pTinEdit.InitNew pEnv
  pTinEdit.SaveAs "H:\New Folder\tin\a3", False '创建放的路径
  pTinEdit.StartEditing
   
 
  Set FeatClass = pFeatureLayer.FeatureClass
 
  Dim pTagFeild As IField
  Set pTagFeild = New Field
 
 
  Dim pHightFeild As IField
  Set pHightFeild = FeatClass.Fields.Field(0)
  'MsgBox pHightFeild.Name
 

'//其中FeatClass.Fields.Field(2), 是要素类中的某一字段  作为Tin的高程信息
  pTinEdit.AddFromFeatureClass FeatClass, Nothing, FeatClass.Fields.Field(2), FeatClass.Fields.Field(0), esriTinMassPoint
  pTinEdit.StopEditing (True)
  pTinEdit.Refresh
 
  Dim pTinNodeCollection As ITinNodeCollection
  Set pTinNodeCollection = pTinEdit
  MsgBox pTinNodeCollection.NodeCount
  Dim ptin As ITin
  Set ptin = pTinEdit
  MsgBox ptin.DataNodeCount
  Dim pNewfeatureclass As IFeatureClass
  Set pNewfeatureclass = OpenFeatureClass_Example

  MsgBox ptin.DataEdgeCount
    ///创建泰森多边形  OpenFeatureClass_Example是 找到的要素类图层
  pTinNodeCollection.ConvertToVoronoiRegions OpenFeatureClass_Example, Nothing, Nothing, "NodeIndex", "asdf"
 
End Sub


//添加要素类的图层函数
Public Function OpenFeatureClass_Example() As IFeatureClass
  Dim pWorkspaceFactory As IWorkspaceFactory
  Set pWorkspaceFactory = New ShapefileWorkspaceFactory
  Dim pFeatureWorkspace As IFeatureWorkspace
  Set pFeatureWorkspace = pWorkspaceFactory.OpenFromFile("H:\New Folder", 0)

'  Dim pWorkspaceEdit  As IWorkspaceEdit
'  Set pWorkspaceEdit = pFeatureWorkspace
'  pWorkspaceEdit.StartEditing True
 
  Dim pFeatureClass As IFeatureClass
  Set pFeatureClass = pFeatureWorkspace.OpenFeatureClass("Vor3")
  Set OpenFeatureClass_Example = pFeatureClass
end function
原文 http://www.gissky.net/blog/user1/yumao/archives/2007/15511.html