Arcgis Engine最短路径分析

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