AE多边形合并

非本人原创.

同事在网上找的
合并速度较快

        /// <summary>
        /// 计算合并面积（去掉岛）
        /// </summary>
        /// <param name="pArrayPolygon">图形集合</param>
        /// <param name="isShowError"></param>
        /// <returns></returns>
        public static IPolygon UnionOrRemoveRingFromPolygon(ArrayList pArrayPolygon, bool isShowError)
        {

            IPolygon pPolygon_Each = null;

            IPolygon pPolygon_Result = null;

            IGeometryCollection pGeometryCollection = null;

            ISegmentCollection pSegmentCollection_Ring = null;

            object oMissing = Type.Missing;

            try
            {

                if (pArrayPolygon == null)

                    return null;

                if (pArrayPolygon.Count == 0)

                    return null;

                pGeometryCollection = new PolygonClass();

                pPolygon_Result = pGeometryCollection as IPolygon;

                for (int i = 0; i < pArrayPolygon.Count; i++)
                {

                    pPolygon_Each = pArrayPolygon[i] as IPolygon;

 

                    IGeometryCollection pGeometryCollection_Temp = null;

                    pGeometryCollection_Temp = pPolygon_Each as IGeometryCollection;

 

                    for (int j = 0; j < pGeometryCollection_Temp.GeometryCount; j++)
                    {

                        pSegmentCollection_Ring = new RingClass();

                        pSegmentCollection_Ring.AddSegmentCollection(pGeometryCollection_Temp.get_Geometry(j) as ISegmentCollection);

                        pGeometryCollection.AddGeometry(pSegmentCollection_Ring as IGeometry, ref oMissing, ref oMissing);

                    }

                }
                pPolygon_Result.SimplifyPreserveFromTo();
                return pPolygon_Result;

            }

            catch (Exception ex)
            {

                //if (isShowError)

                //    MessageBox.Show("合并（去岛）多边形发生错误，错误信息为：->\r\n" + ex.Message,

                //                    "错误信息", MessageBoxButtons.OK, MessageBoxIcon.Error);

                return null;

            }

        }