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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
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