ARCGIS PRO SDK 访问Geometry对象

一、Geometry常用对象

 二、主要类

1、ReadOnlyPartCollection：Polyline 和 Polygon 使用的 ReadOnlySegmentCollection 部件的只读集合，属性成员：​

               方法： GetEnumerator    返回循环访问集合的枚举器。

2、ReadOnlyPointCollection  返回Geometry所有点（拐点或顶点）的MapPoints 的只读集合，属性成员：

 方法： 

三、ReadOnlySegmentCollection ：Segment 类的只读集合。，属性成员：

       方法：GetEnumerator    返回循环访问集合的枚举器

四、GetEnumerator 方法：返回循环访问集合的枚举器

  例如：

1、枚举数据段以获得长度

 Dim polylineParts As ReadOnlyPartCollection = Polyline.Parts

 '枚举数据段以获得长度
 Dim Len As Double = 0
 Dim lsegments As IEnumerator(Of ReadOnlySegmentCollection) = polylineParts.GetEnumerator()
 While lsegments.MoveNext()
     Dim seg As ReadOnlySegmentCollection = lsegments.Current
     For Each s As Segment In seg
         Len += s.Length
         '类型执行一些特定的操作 
         Select Case s.SegmentType
             Case SegmentType.Line
                 MsgBox("SegmentType.SegmentType.Line")
             Case SegmentType.Bezier
                 MsgBox("SegmentType.SegmentType.Bezier")
             Case SegmentType.EllipticArc
                 MsgBox("SegmentType.SegmentType.EllipticArc")
         End Select
     Next
 End While

2、ReadOnlyPointCollection示例

​
Dim segments As IEnumerator(Of MapPoint)
Dim parts As ReadOnlySegmentCollection
Dim x As Double 
Dim y As Double 
segments = polygon1.Points.GetEnumerator
'获取图形所有顶点坐标
Dim ppts As ReadOnlyPointCollection = polygon1.Points
'坐标总数
Dim ppts_Count As long=ppts.Count
'坐标访问
For i = 0 To ppts_Count - 1
    x = ppts.item(i).X
    y = ppts.item(i).Y
Next 

Dim enumPts As IEnumerator(Of MapPoint) = polygon1.Points.GetEnumerator()

Dim coordinates As IReadOnlyList(Of Coordinate2D) = polygon1.Copy2DCoordinatesToList()
Dim coordinate2Ds As IList(Of Coordinate2D) = New List(Of Coordinate2D）(10)
Dim subsetCoordinates2D As ICollection(Of Coordinate2D) = coordinate2Ds

'获取PPTS点集中从ID1开始，取10个坐标点，ID1是从0开始
ppts.Copy2DCoordinatesToList(ID1, 10, subsetCoordinates2D)
'subsetCoordinates2D坐标访问
For i = 0 To subsetCoordinates2D.Count - 1
    pv_x(i) = subsetCoordinates2D(i).X
    pv_y(i) = subsetCoordinates2D(i).Y
Next

​

3、获取多边形外环坐标

'获取
ppv = poly.Points
Dim parts As ReadOnlyPartCollection = poly.Parts
dbx_zds = parts.First.Count()
dbx_zds = parts.First.Count()      '不包含闭合点
Dim coordinate2Ds As IList(Of Coordinate2D) = New List(Of Coordinate2D）
Dim subsetCoordinates2D As ICollection(Of Coordinate2D) = coordinate2Ds
ppv.Copy2DCoordinatesToList(0, dbx_zds + 1, subsetCoordinates2D)   '坐标起点序号，从0开始，共dbx_zds + 1点，含多边形闭合点
’获取的坐标在subsetCoordinates2DIList(Of Coordinate2D)

五、GeometryBag ：是 Geometry 对象的异构集合，成员如下：

方法：