| ArcEngine 最短路径分析（源码） | |
|
using System; using ESRI.ArcGIS.Carto; using ESRI.ArcGIS.Geometry; using ESRI.ArcGIS.Geodatabase; using ESRI.ArcGIS.NetworkAnalysis; namespace GisEditor { /// <summary> /// 最短路径分析 /// </summary> public class ClsPathFinder { private IGeometricNetwork m_ipGeometricNetwork; private IMap m_ipMap; private IPointCollection m_ipPoints; private IPointToEID m_ipPointToEID; private double m_dblPathCost =0; private IEnumNetEID m_ipEnumNetEID_Junctions; private IEnumNetEID m_ipEnumNetEID_Edges; private IPolyline m_ipPolyline; #region Public Function //返回和设置当前地图 public IMap SetOrGetMap { set{ m_ipMap = value;} get{return m_ipMap;} } //打开几何数据集的网络工作空间 public void OpenFeatureDatasetNetwork(IFeatureDataset FeatureDataset) { CloseWorkspace(); if (!InitializeNetworkAndMap(FeatureDataset)) Console.WriteLine( "打开network出错"); } //输入点的集合 public IPointCollection StopPoints { set{m_ipPoints= value;} get{return m_ipPoints;} }
//路径成本 public double PathCost { get {return m_dblPathCost;} }
//返回路径的几何体 public IPolyline PathPolyLine() { IEIDInfo ipEIDInfo; IGeometry ipGeometry; if(m_ipPolyline!=null)return m_ipPolyline;
m_ipPolyline = new PolylineClass(); IGeometryCollection ipNewGeometryColl = m_ipPolyline as IGeometryCollection;
ISpatialReference ipSpatialReference = m_ipMap.SpatialReference; IEIDHelper ipEIDHelper = new EIDHelperClass(); ipEIDHelper.GeometricNetwork = m_ipGeometricNetwork; ipEIDHelper.OutputSpatialReference = ipSpatialReference; ipEIDHelper.ReturnGeometries = true; IEnumEIDInfo ipEnumEIDInfo = ipEIDHelper.CreateEnumEIDInfo(m_ipEnumNetEID_Edges); int count = ipEnumEIDInfo.Count; ipEnumEIDInfo.Reset(); for(int i =0;i<count;i++) { ipEIDInfo = ipEnumEIDInfo.Next(); ipGeometry = ipEIDInfo.Geometry; ipNewGeometryColl.AddGeometryCollection( ipGeometry as IGeometryCollection); } return m_ipPolyline; }
//解决路径 public void SolvePath(string WeightName) { try { int intEdgeUserClassID; int intEdgeUserID; int intEdgeUserSubID; int intEdgeID; IPoint ipFoundEdgePoint; double dblEdgePercent; /*PutEdgeOrigins方法的第二个参数要求是IEdgeFlag类型的数组, * 在VB等其他语言的代码中，只需传人该类型数组的第一个元素即 * 可，但C#中的机制有所不同，需要作出如下修改：使用 * ITraceFlowSolverGEN替代ITraceFlowSolver */ ITraceFlowSolverGEN ipTraceFlowSolver = new TraceFlowSolverClass() as ITraceFlowSolverGEN; INetSolver ipNetSolver = ipTraceFlowSolver as INetSolver; INetwork ipNetwork = m_ipGeometricNetwork.Network; ipNetSolver.SourceNetwork = ipNetwork; INetElements ipNetElements = ipNetwork as INetElements; int intCount = m_ipPoints.PointCount; //定义一个边线旗数组 IEdgeFlag[] pEdgeFlagList = new EdgeFlagClass[intCount]; for(int i = 0;i<intCount ;i++) {
INetFlag ipNetFlag = new EdgeFlagClass()as INetFlag; IPoint ipEdgePoint = m_ipPoints.get_Point(i); //查找输入点的最近的边线 m_ipPointToEID.GetNearestEdge(ipEdgePoint, out intEdgeID,out ipFoundEdgePoint, out dblEdgePercent); ipNetElements.QueryIDs( intEdgeID, esriElementType.esriETEdge, out intEdgeUserClassID, out intEdgeUserID,out intEdgeUserSubID); ipNetFlag.UserClassID = intEdgeUserClassID; ipNetFlag.UserID = intEdgeUserID; ipNetFlag.UserSubID = intEdgeUserSubID; IEdgeFlag pTemp = (IEdgeFlag)(ipNetFlag as IEdgeFlag); pEdgeFlagList[i]=pTemp; } ipTraceFlowSolver.PutEdgeOrigins(ref pEdgeFlagList); INetSchema ipNetSchema = ipNetwork as INetSchema; INetWeight ipNetWeight = ipNetSchema.get_WeightByName(WeightName); INetSolverWeights ipNetSolverWeights = ipTraceFlowSolver as INetSolverWeights; ipNetSolverWeights.FromToEdgeWeight = ipNetWeight;//开始边线的权重 ipNetSolverWeights.ToFromEdgeWeight = ipNetWeight;//终止边线的权重 object [] vaRes =new object[intCount-1]; //通过findpath得到边线和交汇点的集合 ipTraceFlowSolver.FindPath(esriFlowMethod.esriFMConnected, esriShortestPathObjFn.esriSPObjFnMinSum, out m_ipEnumNetEID_Junctions,out m_ipEnumNetEID_Edges, intCount-1, ref vaRes); //计算元素成本 m_dblPathCost = 0; for (int i =0;i<vaRes.Length;i++) { double m_Va =(double) vaRes[i]; m_dblPathCost = m_dblPathCost + m_Va; } m_ipPolyline = null; } catch(Exception ex) { Console.WriteLine(ex.Message); } } #endregion #region Private Function //初始化几何网络和地图 private bool InitializeNetworkAndMap(IFeatureDataset FeatureDataset) { IFeatureClassContainer ipFeatureClassContainer; IFeatureClass ipFeatureClass ; IGeoDataset ipGeoDataset; ILayer ipLayer ; IFeatureLayer ipFeatureLayer; IEnvelope ipEnvelope, ipMaxEnvelope ; double dblSearchTol; INetworkCollection ipNetworkCollection = FeatureDataset as INetworkCollection; int count = ipNetworkCollection.GeometricNetworkCount; //获取第一个几何网络工作空间 m_ipGeometricNetwork = ipNetworkCollection.get_GeometricNetwork(0); INetwork ipNetwork = m_ipGeometricNetwork.Network; if(m_ipMap!=null) { m_ipMap = new MapClass(); ipFeatureClassContainer = m_ipGeometricNetwork as IFeatureClassContainer; count = ipFeatureClassContainer.ClassCount; for(int i =0;i<count;i++) { ipFeatureClass = ipFeatureClassContainer.get_Class(i); ipFeatureLayer = new FeatureLayerClass(); ipFeatureLayer.FeatureClass = ipFeatureClass; m_ipMap.AddLayer( ipFeatureLayer); } } count = m_ipMap.LayerCount; ipMaxEnvelope = new EnvelopeClass(); for(int i =0;i<count;i++) { ipLayer = m_ipMap.get_Layer(i); ipFeatureLayer = ipLayer as IFeatureLayer; ipGeoDataset = ipFeatureLayer as IGeoDataset; ipEnvelope = ipGeoDataset.Extent; ipMaxEnvelope.Union( ipEnvelope); } m_ipPointToEID = new PointToEIDClass(); m_ipPointToEID.SourceMap = m_ipMap; m_ipPointToEID.GeometricNetwork = m_ipGeometricNetwork; double dblWidth = ipMaxEnvelope.Width; double dblHeight = ipMaxEnvelope.Height; if( dblWidth > dblHeight) dblSearchTol = dblWidth / 100; else dblSearchTol = dblHeight / 100; m_ipPointToEID.SnapTolerance = dblSearchTol; return true ; } //关闭工作空间 private void CloseWorkspace() { m_ipGeometricNetwork = null; m_ipPoints = null; m_ipPointToEID = null; m_ipEnumNetEID_Junctions = null; m_ipEnumNetEID_Edges = null; m_ipPolyline = null; } #endregion } } 备注： 在调用该类时的次序： ClsPathFinder m_ipPathFinder; if(m_ipPathFinder==null)//打开几何网络工作空间 { m_ipPathFinder = new ClsPathFinder(); ipMap = this.m_ActiveView.FocusMap; ipLayer = ipMap.get_Layer(0); ipFeatureLayer = ipLayer as IFeatureLayer; ipFDB = ipFeatureLayer.FeatureClass.FeatureDataset; m_ipPathFinder.SetOrGetMap = ipMap; m_ipPathFinder.OpenFeatureDatasetNetwork(ipFDB); } private void ViewMap_OnMouseDown(object sender, ESRI.ArcGIS.MapControl.IMapControlEvents2_OnMouseDownEvent e)//获取地图上鼠标输入的点 { IPoint ipNew ; if( m_ipPoints==null) { m_ipPoints = new MultipointClass(); m_ipPathFinder.StopPoints = m_ipPoints; } ipNew = ViewMap.ActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(e.x,e.y); object o = Type.Missing; m_ipPoints.AddPoint(ipNew,ref o,ref o); } m_ipPathFinder.SolvePath("Weight");//先解析路径 IPolyline ipPolyResult = m_ipPathFinder.PathPolyLine();//最后返回最短路径 |