/// <summary>
/// 获取构成多边形的所有环的点集（包括外环和内环），返回的环内的点集统一按顺时针或逆时针排序
/// </summary>
/// <param name="polygon"></param>
/// <param name="clockwise">时针方向，true为顺时针，false为逆时针</param>
/// <returns></returns>
public static List <List <IPoint> > GetRingPointsByClockwise(this IPolygon4 polygon, bool clockwise)
{
List <List <IPoint> > rings = new List <List <IPoint> >();
//外部环
IGeometryBag exteriorRingGeometryBag = polygon.ExteriorRingBag;//全部外部环
IGeometryCollection exteriorRingGeometryCollection = (IGeometryCollection)exteriorRingGeometryBag;
for (int i = 0; i < exteriorRingGeometryCollection.GeometryCount; i++)
{
IGeometry exteriorRingGeometry = exteriorRingGeometryCollection.get_Geometry(i);
IPointCollection exteriorRingPointCollection = exteriorRingGeometry as IPointCollection;
var exteriorPoints = exteriorRingPointCollection.GetPointList();
if (!clockwise)//外环的点是顺时针排序的，要求逆时针排序时反序List
{
exteriorPoints.Reverse();
}
rings.Add(exteriorPoints); //外部环
var interiorRings = GetInteriorRingPoints(polygon, exteriorRingGeometry as IRing); //内部环
if (clockwise) //内环的点是逆时针排序的，要求顺时针排序时反序List
{
foreach (var ring in interiorRings)
{
ring.Reverse();
}
}
rings.AddRange(interiorRings);
}
return(rings);
}
/// <summary>
/// 获取构成多边形的所有环的点集（包括外环和内环）
/// </summary>
/// <param name="polygon"></param>
/// <returns></returns>
public static List <List <IPoint> > GetRingPoints(this IPolygon4 polygon)
{
List <List <IPoint> > rings = new List <List <IPoint> >();
//外部环
IGeometryBag exteriorRingGeometryBag = polygon.ExteriorRingBag;//全部外部环
IGeometryCollection exteriorRingGeometryCollection = (IGeometryCollection)exteriorRingGeometryBag;
for (int i = 0; i < exteriorRingGeometryCollection.GeometryCount; i++)
{
IGeometry exteriorRingGeometry = exteriorRingGeometryCollection.get_Geometry(i);
IPointCollection exteriorRingPointCollection = exteriorRingGeometry as IPointCollection;
var exteriorPoints = exteriorRingPointCollection.GetPointList();
rings.Add(exteriorPoints); //外部环
rings.AddRange(GetInteriorRingPoints(polygon, exteriorRingGeometry as IRing)); //内部环
}
return(rings);
}
/// <summary>
/// 获取构成环的所有点集
/// </summary>
/// <param name="ring"></param>
/// <returns></returns>
public static List <IPoint> GetRingPoints(this IRing ring)
{
IPointCollection pointCollection = ring as IPointCollection;
return(pointCollection.GetPointList());
}