ArcGIS Engine+最短路径分析（C#源码）

using ESRI.ArcGIS.NetworkAnalysis;

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;}

   }

   //打开网络

   public void OpenFeatureDatasetNetwork(IFeatureDataset FeatureDataset)

   {

    CloseWorkspace();  

    if (!InitializeNetworkAndMap(FeatureDataset))

     Console.WriteLine( "打开出错");

   }

   //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

   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;    

     /*C#中使用

      *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=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);

     //计算成本

     m_dblPathCost = 0;

     for (int i =0;i<vaRes.Length;i++)

     {

      double m_Va =(double) vaRes;

      m_dblPathCost = m_dblPathCost + m_Va;

     }    

     m_ipPolyline = null;

    }

    catch(Exception ex)

    {

     Console.WriteLine(ex.Message);

    }

   }

   #endregion

 

   #region Private Function

   //初始化

   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   ;

 

   }

         

   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：

 

 

ClsPathFinder   m_ipPathFinder;

 

if(m_ipPathFinder==null)//打开网络空间

    {

     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");//解析路径

 

IPolyline ipPolyResult = m_ipPathFinder.PathPolyLine();//返回最短路径