/// <summary>
/// Create a geojson string from the geometry
/// </summary>
/// <param name="geometry"></param>
/// <returns></returns>
public static GeoJSONGeometry CreateFromIGeometry(IGeometry geometry)
{
GeoJSONGeometry jsonGeom = new GeoJSONGeometry();
jsonGeom.Type = geometry.GeometryType.ToString();
StringBuilder sb = new StringBuilder();
if (geometry.GeometryType != esriGeometryType.esriGeometryPoint)
{
sb.Append("[");
}
//Need to work out how to easily rip the coords out of the IGeometry
switch (geometry.GeometryType)
{
case esriGeometryType.esriGeometryPoint:
IPoint pt = (IPoint)geometry;
sb.Append(string.Format("[{0}, {1}]", Math.Round(pt.X, 5), Math.Round(pt.Y, 5)));
jsonGeom.Type = "Point";
break;
case esriGeometryType.esriGeometryLine:
IPolyline line = geometry as IPolyline;
if (line == null)
{
return(null);
}
line.Densify(-1, -1); //make sure it's all straight line segments
line.Weed(20); //weed out some vertices
line.SimplifyNetwork(); //make sure it is simple
IPointCollection points = line as IPointCollection;
for (int i = 0; i < points.PointCount; i++)
{
IPoint point = points.get_Point(i);
if (sb.Length > 1)
{
sb.Append(",");
}
sb.Append(string.Format("[{0}, {1}]", Math.Round(point.X, 4), Math.Round(point.Y, 4)));
}
jsonGeom.Type = "LineString";
break;
case esriGeometryType.esriGeometryPolygon:
IPolygon4 poly = geometry as IPolygon4;
if (poly == null)
{
return(null);
}
poly.Densify(-1, -1); //make sure it is all straight line segments
poly.Weed(20); //weed out some vertices
poly.SimplifyPreserveFromTo(); //make sure it's simple
//We aren't gonna deal with interior rings right now (ie - no holes in polygons)
IGeometryBag multiRing = poly.ExteriorRingBag;
IEnumGeometry exteriorRingsEnum = multiRing as IEnumGeometry;
exteriorRingsEnum.Reset();
IRing currentExteriorRing = exteriorRingsEnum.Next() as IRing;
while (currentExteriorRing != null)
{
if (!currentExteriorRing.IsClosed)
{
currentExteriorRing.Close();
}
IPointCollection multiRingPoints = currentExteriorRing as IPointCollection;
for (int pointIdx = 0; pointIdx < multiRingPoints.PointCount; pointIdx++)
{
IPoint multiRingPoint = multiRingPoints.get_Point(pointIdx);
//coords.Add(new GisSharpBlog.NetTopologySuite.Geometries.Coordinate(Math.Round(multiRingPoint.X, 5), Math.Round(multiRingPoint.Y, 5)));
if (sb.Length > 1)
{
sb.Append(",");
}
sb.Append(string.Format("[{0}, {1}]", Math.Round(multiRingPoint.X, 4), Math.Round(multiRingPoint.Y, 4)));
}
currentExteriorRing = exteriorRingsEnum.Next() as IRing;
}
jsonGeom.Type = "Polygon";
break;
}
if (geometry.GeometryType != esriGeometryType.esriGeometryPoint)
{
sb.Append("]");
}
jsonGeom.coordinates = sb.ToString();
return(jsonGeom);
}