/// <summary>
/// 绘制区域多边形
/// </summary>
private void StartDraw()
{
Clear();
IGeometryFactory geometryFactory = new GeometryFactory();
IPolygon polygon = (IPolygon)geometryFactory.CreateGeometry(gviGeometryType.gviGeometryPolygon, gviVertexAttribute.gviVertexAttributeNone);
ISurfaceSymbol surfaceSymbol = new SurfaceSymbol()
{
Color = System.Drawing.Color.Yellow
};
IObjectManager objectManager = _AxRenderControl.ObjectManager;
_RenderPolygon = objectManager.CreateRenderPolygon(polygon, surfaceSymbol, rootId);
_RenderPolygon.HeightStyle = gviHeightStyle.gviHeightOnTerrain;
_RenderPolygon.MaxVisibleDistance = double.MaxValue;
_RenderPolygon.MinVisiblePixels = 3;
_AxRenderControl.ObjectEditor.StartEditRenderGeometry(_RenderPolygon, gviGeoEditType.gviGeoEditCreator);
}