Hallo mal wieder, folgende Klasse hat einige Events die ich gerne anwenden würde. Nun erzeuge ich z.B. folgendes Event:
Und folgende Methode
Nun, ich weiß nicht was ich mit diesem args.Edge.Target anfangen muß, weise ich das zu, oder was macht man. Ich verstehe einfach nicht was ich in dieser Methode zu tun habe, damit auch das passiert, was sollte.
Könnt Ihr bitte helfen?
Euer JAck
C#:
QuickGraph.Algorithms.Search.DepthFirstSearchAlgorithm depthsearch = new QuickGraph.Algorithms.Search.DepthFirstSearchAlgorithm(g);
depthsearch.BackEdge+=new EdgeHandler(depthsearch_BackEdge);
C#:
private void depthsearch_BackEdge(object sender,QuickGraph.Concepts.EdgeEventArgs args)
{
//args.Edge.Target;
}
C#:
namespace QuickGraph.Algorithms.Search
{
using System;
using System.Collections;
using System.Collections.Specialized;
using QuickGraph.Collections;
using QuickGraph.Concepts;
using QuickGraph.Concepts.Algorithms;
using QuickGraph.Concepts.Traversals;
using QuickGraph.Concepts.Visitors;
/// <summary>
/// The DepthFirstSearchAlgorithm performs a depth-first traversal of the
/// vertices in a directed graph.
/// </summary>
/// <remarks>
/// <para>
/// When possible, a depth-first traversal chooses a vertex adjacent to
/// the current vertex to visit next. If all adjacent vertices have
/// already been discovered, or there are no adjacent vertices,
/// then the algorithm backtracks to the last vertex that had undiscovered
/// neighbors. Once all reachable vertices have been visited, the algorithm
/// selects from any remaining undiscovered vertices and continues the
/// traversal. The algorithm finishes when all vertices have been visited.
/// </para>
/// <para>
/// Depth-first search is useful for categorizing edges in a graph,
/// and for imposing an ordering on the vertices.
/// </para>
/// <para>
/// Similar to the <seealso cref="BreadthFirstSearchAlgorithm"/>, color
/// markers are used to keep track of which vertices have been discovered.
/// White marks vertices that have yet to be discovered,
/// gray marks a vertex that is discovered but still has vertices adjacent
/// to it that are undiscovered. A black vertex is discovered vertex that
/// is not adjacent to any white vertices.
/// </para>
/// <para>The main loop pseudo-code is as follows:
/// <code>
/// Graph G;
/// DFS(Vertex s)
/// {
/// // initialize vertex colors
/// foreach(Vertex v in G.Vertices)
/// {
/// Colors[v] = White;
/// InitializeVertex(v); // event
/// }
///
/// // if there is a starting vertex, visit it
/// if (s != null)
/// {
/// StartVertex(s); // event
/// Visit(s);
/// }
///
/// // visit all vertices, if not previously visited
/// foreach(Vertex v in G.Vertices)
/// {
/// if (Colors[v] != White)
/// {
/// StartVertex(v); // event
/// Visit(v);
/// }
/// }
/// }
/// </code>
/// </para>
/// <para>The Visit method pseudo-code is as follows:
/// <code>
/// Visit( Vertex u)
/// {
/// Colors[u] = Gray;
/// DiscoverVertex(u); // event
///
/// // examine edges
/// foreach(Edge e in u.OutEdges)
/// {
/// ExamineEdge(e); // event
/// if (Colors[u] == White)
/// {
/// TreeEdge(e); // event
/// Visit(e.Target);
/// }
/// else if (Colors[u] == Gray)
/// {
/// BackEdge(e); // event
/// }
/// else
/// ForwardOrCrossEdge(e); // event
/// }
///
/// Colors[u] = Black;
/// FinishVertex(u); // event
/// }
/// </code>
/// </para>
/// <para>In itself the algorithm does not take action, it is the user
/// job to attach handlers to the different events that take part during
/// the algorithm:
/// <list type="bullet">
/// <listheader>
/// <term>Event</term>
/// <description>When</description>
/// </listheader>
/// <item>
/// <term>InitializeVertex</term>
/// <description>Invoked on every vertex of the graph before the start of the graph
/// search.</description>
/// </item>
/// <item>
/// <term>StartVertex</term>
/// <description>Invoked on the source vertex once before the start of the search.</description>
/// </item>
/// <item>
/// <term>DiscoverVertex</term>
/// <description>Invoked when a vertex is encountered for the first time. </description>
/// </item>
/// <item>
/// <term>ExamineEdge</term>
/// <description>Invoked on every out-edge of each vertex after it is discovered.</description>
/// </item>
/// <item>
/// <term>TreeEdge</term>
/// <description>Invoked on each edge as it becomes a member of the edges that form
/// the search tree. If you wish to record predecessors, do so at this
/// event point. </description>
/// </item>
/// <item>
/// <term>BackEdge</term>
/// <description>Invoked on the back edges in the graph. </description>
/// </item>
/// <item>
/// <term>FowardOrCrossEdge</term>
/// <description>Invoked on forward or cross edges in the graph.
/// (In an undirected graph this method is never called.)</description>
/// </item>
/// <item>
/// <term>FinishVertex</term>
/// <description>Invoked on a vertex after all of its out edges have been added to
/// the search tree and all of the adjacent vertices have been
/// discovered (but before their out-edges have been examined).</description>
/// </item>
/// </list>
/// </para>
/// <para>
/// Predifined visitors, such as <seealso cref="QuickGraph.Concepts.Visitors.IPredecessorRecorderVisitor"/>
/// and <seealso cref="QuickGraph.Concepts.Visitors.ITimeStamperVisitor"/>
/// can be used with this algorithm.
/// </para>
/// <para>This algorithm is directly inspired from the
/// BoostGraphLibrary implementation.
/// </para>
/// </remarks>
public class DepthFirstSearchAlgorithm :
IAlgorithm,
IPredecessorRecorderAlgorithm,
ITimeStamperAlgorithm,
IVertexColorizerAlgorithm,
ITreeEdgeBuilderAlgorithm
{
private IVertexListGraph m_VisitedGraph;
private VertexColorDictionary m_Colors;
/// <summary>
/// A depth first search algorithm on a directed graph
/// </summary>
/// <param name="g">The graph to traverse</param>
/// <exception cref="ArgumentNullException">g is null</exception>
public DepthFirstSearchAlgorithm(IVertexListGraph g)
{
if (g == null)
throw new ArgumentNullException("g");
m_VisitedGraph = g;
m_Colors = new VertexColorDictionary();
}
/// <summary>
/// A depth first search algorithm on a directed graph
/// </summary>
/// <param name="g">The graph to traverse</param>
/// <param name="colors">vertex color map</param>
/// <exception cref="ArgumentNullException">g or colors are null</exception>
public DepthFirstSearchAlgorithm(
IVertexListGraph g,
VertexColorDictionary colors
)
{
if (g == null)
throw new ArgumentNullException("g");
if (colors == null)
throw new ArgumentNullException("Colors");
m_VisitedGraph = g;
m_Colors = colors;
}
/// <summary>
/// Visited graph
/// </summary>
public IVertexListGraph VisitedGraph
{
get
{
return m_VisitedGraph;
}
}
Object IAlgorithm.VisitedGraph
{
get
{
return this.VisitedGraph;
}
}
/// <summary>
/// Vertex color map
/// </summary>
public VertexColorDictionary Colors
{
get
{
return m_Colors;
}
}
/// <summary>
/// IVertexColorizerAlgorithm implementation
/// </summary>
IDictionary IVertexColorizerAlgorithm.Colors
{
get
{
return this.Colors;
}
}
#region Events
/// <summary>
/// Invoked on every vertex of the graph before the start of the graph
/// search.
/// </summary>
public event VertexHandler InitializeVertex;
/// <summary>
/// Invoked on the source vertex once before the start of the search.
/// </summary>
public event VertexHandler StartVertex;
/// <summary>
/// Invoked when a vertex is encountered for the first time.
/// </summary>
public event VertexHandler DiscoverVertex;
/// <summary>
/// Invoked on every out-edge of each vertex after it is discovered.
/// </summary>
public event EdgeHandler ExamineEdge;
/// <summary>
/// Invoked on each edge as it becomes a member of the edges that form
/// the search tree. If you wish to record predecessors, do so at this
/// event point.
/// </summary>
public event EdgeHandler TreeEdge;
/// <summary>
/// Invoked on the back edges in the graph.
/// </summary>
public event EdgeHandler BackEdge;
/// <summary>
/// Invoked on forward or cross edges in the graph.
/// (In an undirected graph this method is never called.)
/// </summary>
public event EdgeHandler ForwardOrCrossEdge;
/// <summary>
/// Invoked on a vertex after all of its out edges have been added to
/// the search tree and all of the adjacent vertices have been
/// discovered (but before their out-edges have been examined).
/// </summary>
public event VertexHandler FinishVertex;
#endregion
/// <summary>
/// Execute the DFS search.
/// </summary>
public void Compute()
{
Compute(null);
}
/// <summary>
/// Execute the DFS starting with the vertex s
/// </summary>
/// <param name="s">Starting vertex</param>
public void Compute(IVertex s)
{
// put all vertex to white
foreach(IVertex u in VisitedGraph.Vertices)
{
Colors[u] = GraphColor.White;
if (this.InitializeVertex != null)
InitializeVertex(this, new VertexEventArgs(u));
}
// if there is a starting vertex, start whith him:
if (s != null)
{
if (this.StartVertex != null)
StartVertex(this, new VertexEventArgs(s));
Visit(s);
}
// process each vertex
foreach(IVertex u in VisitedGraph.Vertices)
{
if (Colors[u] == GraphColor.White)
{
if (this.StartVertex != null)
StartVertex(this, new VertexEventArgs(u));
Visit(u);
}
}
}
/// <summary>
/// Does a depth first search on the vertex u
/// </summary>
/// <param name="u">vertex to explore</param>
/// <exception cref="ArgumentNullException">u cannot be null</exception>
public void Visit(IVertex u)
{
if (u==null)
throw new ArgumentNullException("u");
IVertex v = null;
Colors[u] = GraphColor.Gray;
VertexEventArgs uArgs = new VertexEventArgs(u);
if (this.DiscoverVertex != null)
DiscoverVertex(this, uArgs);
foreach(IEdge e in VisitedGraph.OutEdges(u))
{
EdgeEventArgs eArgs = new EdgeEventArgs(e);
if (this.ExamineEdge != null)
ExamineEdge(this, eArgs);
v = e.Target;
if (Colors[v] == GraphColor.White)
{
if (this.TreeEdge != null)
TreeEdge(this, eArgs);
Visit(v);
}
else if (Colors[v] == GraphColor.Gray)
{
if(this.BackEdge!=null)
BackEdge(this,eArgs);
}
else
{
if (this.ForwardOrCrossEdge!=null)
ForwardOrCrossEdge(this,eArgs);
}
}
Colors[u] = GraphColor.Black;
if (this.FinishVertex != null)
FinishVertex(this, uArgs);
}
/// <summary>
/// Registers the predecessors handler
/// </summary>
/// <param name="vis"></param>
public void RegisterPredecessorRecorderHandlers(IPredecessorRecorderVisitor vis)
{
if (vis == null)
throw new ArgumentNullException("visitor");
InitializeVertex += new VertexHandler(vis.InitializeVertex);
TreeEdge += new EdgeHandler(vis.TreeEdge);
}
/// <summary>
///
/// </summary>
/// <param name="vis"></param>
public void RegisterTimeStamperHandlers(ITimeStamperVisitor vis)
{
if (vis == null)
throw new ArgumentNullException("visitor");
DiscoverVertex += new VertexHandler(vis.DiscoverVertex);
FinishVertex += new VertexHandler(vis.FinishVertex);
}
/// <summary>
///
/// </summary>
/// <param name="vis"></param>
public void RegisterVertexColorizerHandlers(IVertexColorizerVisitor vis)
{
if (vis == null)
throw new ArgumentNullException("visitor");
InitializeVertex += new VertexHandler(vis.InitializeVertex);
DiscoverVertex += new VertexHandler(vis.DiscoverVertex);
FinishVertex += new VertexHandler(vis.FinishVertex);
}
/// <summary>
///
/// </summary>
/// <param name="vis"></param>
public void RegisterTreeEdgeBuilderHandlers(ITreeEdgeBuilderVisitor vis)
{
if (vis == null)
throw new ArgumentNullException("visitor");
TreeEdge += new EdgeHandler(vis.TreeEdge);
}
}
}
C#:
using System;
namespace QuickGraph.Concepts
{
/// <summary>
/// Event argument that contains a <seealso cref="Vertex"/>.
/// </summary>
public class VertexEventArgs : EventArgs
{
private IVertex m_Vertex;
/// <summary>
/// Builds a new event argument object
/// </summary>
/// <param name="v">vertex to store</param>
public VertexEventArgs(IVertex v)
{
if (v == null)
throw new ArgumentNullException("vertex");
m_Vertex = v;
}
/// <summary>
/// Vertex passed to the event
/// </summary>
public IVertex Vertex
{
get
{
return m_Vertex;
}
}
}
/// <summary>
/// Delegate that handles an event that sends a vertex.
/// </summary>
public delegate void VertexHandler(Object sender, VertexEventArgs args);
/// <summary>
/// Event argument that contains an <seealso cref="IEdge"/>.
/// </summary>
public class EdgeEventArgs : EventArgs
{
private IEdge m_Edge;
/// <summary>
/// Create a new event argument
/// </summary>
/// <param name="e">edge to store</param>
public EdgeEventArgs(IEdge e)
{
if (e == null)
throw new ArgumentNullException("edge");
m_Edge = e;
}
/// <summary>
/// Edge passed to the event
/// </summary>
public IEdge Edge
{
get
{
return m_Edge;
}
}
}
/// <summary>
/// Delegate that handles an edge that sends a vertex.
/// </summary>
public delegate void EdgeHandler(Object sender, EdgeEventArgs args);
}Könnt Ihr bitte helfen?
Euer JAck
Zuletzt bearbeitet:
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