Dim stations As New Collection
Dim trains As New Collection
For i = 1 To 60
Dim new_station As New station
With new_station
.id = S_stationsDataSet.Node_Table.Rows(i - 1)(0)
.name = S_stationsDataSet.Node_Table.Rows(i - 1)(1)
.t = S_stationsDataSet.Node_Table.Rows(i - 1)(4)
.name_t = new_station.name & new_station.t
.x = S_stationsDataSet.Node_Table.Rows(i - 1)(2)
.y = S_stationsDataSet.Node_Table.Rows(i - 1)(3)
End With
stations.Add(new_station, new_station.name_t)
Next
Dim a, c, l, n As String
Dim m, b As Single
For i = 1 To 78 Step 2
a = S_trainsDataSet.T.Rows(1)(i)
b = S_trainsDataSet.T.Rows(1)(i + 1)
c = a & b
l = S_trainsDataSet.T.Rows(2)(i)
m = S_trainsDataSet.T.Rows(2)(i + 1)
n = l & m
Dim new_train As New train
With new_train
.id = S_trainsDataSet.T.Rows(0)(i)
.src_t = S_trainsDataSet.T.Rows(1)(i + 1)
.dst_t = S_trainsDataSet.T.Rows(2)(i + 1)
.src = stations.Item(c)
.dst = stations.Item(n)
End With
trains.Add(new_train, new_train.id.ToString())
Next
For Each station In stations
station.come = New Collection
station.go = New Collection
For Each train In trains
If train.src.name_t = station.name_t Then
station.go.add(train, train.id.ToString())
End If
If train.dst.name_t = station.name_t Then
station.come.add(train, train.id.ToString())
End If
Next
Next
vb：第1项中的项目的属性是第2个集合中的项目，反之亦然..当我删除项目时......在其他集合中它没有被更新为null
我们如何将两个馆藏的项目相互链接
答案 0 :(得分：1)
经过漫长的等待，我终于有一段时间完成了这个。对于漫长的等待非常抱歉。
我不知道它是否完全符合您的要求，但它会使train和station类更加协同工作。
由于您拥有如此多的馆藏（因为他们甚至在您的班级中），因此很难全部更新。我建议您使用Dictionary(Of TKey, TValue)并在train类中使用布尔属性。您的词典将如下所示：Dictionary(Of station, List(Of train))。
首先，我们需要一些扩展方法，以便稍后帮助我们找到并遍历站点和列车。我们将从一个函数开始，通过指定它的名称找到一个电台。
创建一个新的Module并在以下位置添加此代码：
''' <summary>
''' Finds a station by it's name.
''' </summary>
''' <param name="StationCollection">The dictionary to look for the station in.</param>
''' <param name="Name">The name of the station to find.</param>
''' <remarks></remarks>
<System.Runtime.CompilerServices.Extension()> _
Public Function FindStationByName(ByRef StationCollection As Dictionary(Of station, List(Of train)), ByVal Name As String) As station
Name = Name.ToLower() 'ToLower() provides case-insensitive checking.
'Iterating through a Dictionary requires iterating through it's keys, as it's not index based.
For Each k As station In StationCollection.Keys
If k.name_t.ToLower() = Name Then
Return k
End If
Next
Return Nothing
End Function
然后我们需要通过它的id或它的名字来查找火车的扩展方法。我们还可以查找与特定车站相关的所有列车。在与上面相同的模块中添加：
''' <summary>
''' Finds a train by it's ID.
''' </summary>
''' <param name="TrainCollection">The list to look for the train in.</param>
''' <param name="Id">The ID of the train to find.</param>
''' <remarks></remarks>
<System.Runtime.CompilerServices.Extension()> _
Public Function FindTrainById(ByRef TrainCollection As List(Of train), ByVal Id As Integer) As train
For Each t As train In TrainCollection
If t.id = Id Then
Return t
End If
Next
Return Nothing
End Function
''' <summary>
''' Finds a train by it's name.
''' </summary>
''' <param name="TrainCollection">The list to look for the train in.</param>
''' <param name="TrainName">The name of the train to find.</param>
''' <remarks></remarks>
<System.Runtime.CompilerServices.Extension()> _
Public Function FindTrainByName(ByRef TrainCollection As List(Of train), ByVal TrainName As String) As train
TrainName = TrainName.ToLower()
For Each t As train In TrainCollection
If t.name_t = TrainName Then
Return t
End If
Next
Return Nothing
End Function
''' <summary>
''' Finds all trains linked to the specified station.
''' </summary>
''' <param name="StationCollection">The dictionary to look for the station in.</param>
''' <param name="StationName">The name of the station which's trains to find.</param>
''' <remarks></remarks>
<System.Runtime.CompilerServices.Extension()> _
Public Function FindTrainsByStation(ByRef StationCollection As Dictionary(Of station, List(Of train)), ByVal StationName As String) As List(Of train)
StationName = StationName.ToLower()
For Each k As station In StationCollection.Keys
If k.name_t.ToLower() = StationName Then
Return StationCollection(k)
End If
Next
Return Nothing
End Function
最后，我们需要一种扩展方法来从所有站点中移除火车。此扩展方法稍后将由RemoveAll()类中的RemoveAllByName()和train方法使用。
''' <summary>
''' Removes a trains link from all stations.
''' </summary>
''' <param name="StationCollection">The dictionary of stations which's links to this train to remove.</param>
''' <param name="train">The train to remove.</param>
''' <param name="MatchName">If true, match by the train's name instead of it's ID.</param>
''' <remarks></remarks>
<System.Runtime.CompilerServices.Extension()> _
Public Sub RemoveTrainFromAllStations(ByVal StationCollection As Dictionary(Of station, List(Of train)), ByVal train As train, ByVal MatchName As Boolean)
For Each k As station In StationCollection.Keys
For i = 0 To StationCollection(k).Count - 1
Dim t As train = StationCollection(k)(i)
If MatchName = False Then 'Wether to match against the train's name or id.
If t.id = train.id Then
t.Remove()
End If
Else
If t.name_t = train.name_t Then
t.Remove()
End If
End If
Next
Next
End Sub
现在上课。
将词典引用传递给station和train类也可以帮助您创建检查哪些列车属于哪个站等的功能。通过这样做，您可以将这些类与词典一起使用，你甚至可以围绕这个做另一个包装类，以减少＆＃34;凌乱＆＃34;甚至更多。
您还需要覆盖Equals和GetHashCode方法，以便字典和哈希表能够正确查找您的密钥。
这只是示例代码，所以我在这里没有包含您的属性：
Public Class train
Private StationCollection As Dictionary(Of station, List(Of train)) 'Storing the main dictionary.
Private _parent As station
''' <summary>
''' Wether this train is departing or arriving.
''' </summary>
''' <remarks></remarks>
Public Property Departing As Boolean = False
''' <summary>
''' The station that owns this train (multiple stations can own trains with the same names and IDs).
''' This is mainly used for internal functions.
''' </summary>
''' <remarks></remarks>
Public ReadOnly Property ParentStation As station
Get
Return _parent
End Get
End Property
''' <summary>
''' Initializes a new instance of the train class.
''' </summary>
''' <param name="StationCollection">The main dictionary containing this train and it's station.</param>
''' <param name="ParentStation">The station that owns this train (multiple stations can own trains with the same names and IDs).</param>
''' <remarks></remarks>
Public Sub New(ByRef StationCollection As Dictionary(Of station, List(Of train)), ByVal ParentStation As station)
Me.StationCollection = StationCollection
Me._parent = ParentStation
End Sub
''' <summary>
''' Removes this train from it's station.
''' </summary>
''' <remarks></remarks>
Public Sub Remove()
Me.StationCollection(ParentStation).Remove(Me)
End Sub
''' <summary>
''' Removes this, and all other trains having the same ID as this, from all stations in the main dictionary.
''' </summary>
''' <remarks></remarks>
Public Sub RemoveAll()
Me.StationCollection.RemoveTrainFromAllStations(Me, False)
End Sub
''' <summary>
''' Removes this, and all other trains having the same name as this, from all stations in the main dictionary.
''' </summary>
''' <remarks></remarks>
Public Sub RemoveAllByName()
Me.StationCollection.RemoveTrainFromAllStations(Me, True)
End Sub
'the rest of your code...
'Overriding Equals() and GetHashCode(), comparison will be performed by comparing two trains' id's.
Public Overrides Function Equals(obj As Object) As Boolean
Return obj IsNot Nothing AndAlso obj.GetType() Is GetType(train) AndAlso DirectCast(obj, train).id = Me.id
End Function
Public Overrides Function GetHashCode() As Integer
Return Me.id.GetHashCode()
End Function
End Class
station类：
Public Class station
Private StationCollection As Dictionary(Of station, List(Of train)) 'Linking this station to the main Dictionary.
''' <summary>
''' Gets a list of trains arriving at this station. Modifying the returned list will NOT affect the main dictionary or it's stations.
''' </summary>
''' <remarks></remarks>
Public ReadOnly Property ArrivingTrains As List(Of train)
Get
Return Me.GetTrainsByType(False)
End Get
End Property
''' <summary>
''' Gets a list of trains departing from this station. Modifying the returned list will NOT affect the main dictionary or it's stations.
''' </summary>
''' <remarks></remarks>
Public ReadOnly Property DepartingTrains As List(Of train)
Get
Return Me.GetTrainsByType(True)
End Get
End Property
''' <summary>
''' Gets all trains of the specified type that are linked to this station.
''' </summary>
''' <param name="Departing">Wether to get all departing trains or all arriving trains.</param>
''' <remarks></remarks>
Private Function GetTrainsByType(ByVal Departing As Boolean) As List(Of train)
Dim TrainList As List(Of train) = StationCollection(Me) 'Getting all trains for this station.
Dim ReturnList As New List(Of train)
For Each t As train In TrainList
If t.Departing = Departing Then
ReturnList.Add(t)
End If
Next
Return ReturnList
End Function
''' <summary>
''' Removes this station and all links to trains arriving or departing from it.
''' </summary>
''' <remarks></remarks>
Public Sub Remove()
For Each t As train In StationCollection(Me) 'Iterate though all the trains for this station.
GetType(train).GetField("_parent", Reflection.BindingFlags.Instance Or Reflection.BindingFlags.NonPublic).SetValue(t, Nothing) 'Use reflection to set the train's parent to Nothing.
Next
StationCollection.Remove(Me)
End Sub
''' <summary>
''' Initializes a new instance of the station class.
''' </summary>
''' <param name="StationCollection">The main dictionary containing this train and it's station.</param>
''' <remarks></remarks>
Public Sub New(ByRef StationCollection As Dictionary(Of station, List(Of train)))
Me.StationCollection = StationCollection
End Sub
'the rest of your code...
'Overriding Equals() and GetHashCode(), comparison will be performed by comparing two stations' names.
Public Overrides Function Equals(obj As Object) As Boolean
Return obj IsNot Nothing AndAlso obj.GetType() Is GetType(station) AndAlso DirectCast(obj, station).name_t = Me.name_t
End Function
Public Overrides Function GetHashCode() As Integer
Return Me.name_t.GetHashCode()
End Function
End Class
在向字典中添加项目时，首先必须初始化新的station类，然后创建新的train类，将ParentStation参数指向刚刚创建的工作站
例如：
Dim MainDictionary As New Dictionary(Of station, List(Of train)) 'Create the dictionary (only do this once, unless you need multiple of course).
Dim new_station As New station(MainDictionary) 'Create a new station.
new_station.name = "Station 1"
MainDictionary.Add(new_station, New List(Of train))
Dim new_train As New train(MainDictionary, new_station) 'Create a new train.
new_train.id = 3
new_train.name_t = "Train 1"
new_train.Departing = True 'This train is leaving from the station.
MainDictionary(new_station).Add(new_train) 'Add the train to the station.
在......
时使用扩展方法您希望按名称找到特定的电台。
例如：
Dim st As station = MainDictionary.FindStationByName("Station 1")
您想根据它的ID或名称查找火车。
例如：
Dim t As train = MainDictionary.FindStationByName("Station 1").ArrivingTrains.FindTrainById(3)
Dim t2 As train = MainDictionary.FindStationByName("Station 1").ArrivingTrains.FindTrainByName("Train 1")
或者当您想要从特定电台（按照其名称）获取所有列车时。
例如：
Dim trains As List(Of train) = MainDictionary.FindTrainsByStation("Station 1")
train类 - <强> StationCollection
<强> _parent
<强>出发
<强> ParentStation
_parent。删除（）
<强>的removeAll（）
<强> RemoveAllByName（）
RemoveAll()相同，但与列车匹配＆＃39;名字而不是他们的ID。station类 - <强> StationCollection
train类相同。<强> ArrivingTrains
<强> DepartingTrains
<强> GetTrainsByType（）
删除（）
_parent字段无效）。希望这有帮助！很抱歉这么久。