每次我使用某个类别，如Artikel，如下：
Public Class Artikel
Property ID As Integer
Property Nummer As String
Property Name As String
Property Position As Integer
End Class
对于这样的课程，我想要收集课程。我希望拥有的功能如下：
--> Add (passing Artikel object)
--> Remove (passing Artikel object)
--> Sort entire collection (based on Position property desc/asc)
--> Compare two Artikels (pass by Artikels and tell by which property has to be compared)
--> Check whether two artikels equals
--> Every added artikel has to be marked by Key (so maybe dictionary)? <key><Artikel>
--> Remove Artikel (passing by Key index)
你能告诉我或者甚至更好地提供收集课的例子来传递这些要求吗？
编辑：启动：
Artikel的收藏：
Option Strict On
Public Class Articles
Public Property collection As Dictionary(Of Integer, Artikel)
Sub New()
'Initiate new collection
collection = New Dictionary(Of Integer, Artikel)
End Sub
'Add new Artikel to collection
Public Function AddToCollection(ByVal artikel As Artikel) As Boolean
collection.Add(artikel)
Return True
End Function
'Remove specific Artikel
Public Sub RemoveFromCollectionByArtikel(artikel As Artikel)
If Not IsNothing(collection) Then
collection.Remove(artikel)
End If
End Sub
'Get collection
Public Function GetCollection() As Dictionary(Of Integer, Artikel)
Return collection
End Function
'Sort collection by property position
Public Sub SortByPosition()
collection.Sort()
End Sub
'Remove specific sending keys and then reorder them
Public Sub RemoveAllMarkedAsDeleted(keys As List(Of Integer))
'-- Check whther anything has been marked as deleted
If keys.Count > 0 Then
For Each row In keys
collection.Remove(row)
Next
ReorderKeys()
End If
'Reorder all Artikels in collection
Private Sub ReorderKeys()
Dim newCollection As New Dictionary(Of Integer, Artikel)
Dim index As Integer = 0
For Each collitem In collection
newCollection.Add(index, collitem.Value)
index += 1
Next
collection.Clear()
collection = newCollection
End Sub
End Class
Artikel类（另外我实现了IComparable以便能够排序）
Option Strict On
Public Class Artikel
Implements IComparable(Of Artikel)
Property ID As Integer
Property Nummer As String
Property Name As String
Property Position As Integer
Public Function CompareTo(pother As Artikel) As Integer Implements IComparable(Of Artikel).CompareTo 'we can sort because of this
Return String.Compare(Me.Position, pother.Position)
End Function
Public Shared Function FindPredicate(ByVal partikel As Artikel) As Predicate(Of Artikel)
Return Function(partikel2 As Artikel) partikel.ID = partikel2.ID
End Function
Public Shared Function FindPredicateByUserId(ByVal partikel As String) As Predicate(Of Artikel)
Return Function(partikel2 As Artikel) partikel = partikel2.ID
End Function
End Class
答案 0 :(得分：0)
创建班级
sample_submission.csv创建另一个包含私有列表并向其添加子例程的类
Public Class Artikel
Property ID As Integer
Property Nummer As String
Property Name As String
Property Position As Integer
sub new (_ID as integer, _Nummer as string, _Name as string, _Position as integer)
ID = _ID
Nummer = _Nummer
Name = _Name
Position = _Position
End Sub
End Class
然后使用你的列表类。
Public Class ArtikelList
Private _List as new list (of Artikel)
Public sub remove(Key as integer)
Dim obj as Artikel = nothing
for each x as Artikel in _List
if x.ID = Key then
obj = x
exit for
end if
Next
if not isnothing(obj) then
_List.remove(obj)
end if
End sub
Sub Add(obj as Artikel)
Dim alreadyDeclared as boolean = falsse
for each x as Artikel in _List
if x.ID = obj.id then
alreadyDeclared = true
exit for
end if
Next
if not AlreadyDeclared then
_List.add(obj)
Else
'Somehow inform the user of the duplication if need be.
end if
End sub
End Class
我只添加了一个子例程作为示例。我希望它有所帮助，但可以随意提出更多示例例程。
这也可以通过创建一个继承自列表类的类来完成，公开所有列表类功能，但是通过使用此方法，您将被迫创建将要使用的每个子例程。这样，您只能使用专门为Artikel对象处理而创建的例程。
检查两个Artikels是否相等
dim L as new ArtikelList
L.add(new Artikel(1280, "AFKforever!", "Prof.FluffyButton", 96))
L.remove(1280)
使用它像：
Public Class Artikel
Property ID As Integer
Property Nummer As String
Property Name As String
Property Position As Integer
sub new (_ID as integer, _Nummer as string, _Name as string, _Position as integer)
ID = _ID
Nummer = _Nummer
Name = _Name
Position = _Position
End Sub
End Class
Public Overrides Overloads Function Equals(obj As Object) As Boolean
If obj Is Nothing OrElse Not Me.GetType() Is obj.GetType() Then
Return False
else
dim _obj as artikel = obj
if Me.ID = _obj.ID then
Return true
else Return False
End If
End Function
End Class
答案 1 :(得分：0)
部分内容看起来不错，但我最终会做的有点不同。首先，考虑对item类的重载，使它们更容易创建和默认初始化：
Public Class Article
Property ID As Integer = -1
Property Key As String = ""
Property Name As String = ""
Property Position As Integer = -1
Property PubDate As DateTime = DateTime.Minimum
Public Sub New()
End Sub
' whatever minimum data a new item requires
Public Sub New(k As String, n As String)
Key = k
Name = n
End Sub
' full initialization:
Public Sub New(k As String, n As String, pos As Int32,
pubDt As DateTime)
...
End Sub
End Class
我添加了一些属性的属性，我怀疑＆＃34; Nummer＆＃34;可能是＆＃34; Key＆＃34;在OP中提到，但不管它是什么，如果它具有一定的重要性，我会将它添加到Article类作为该名称。
您可能需要一个简单的ctor进行序列化（???）。其中一些将找到并使用Private无参数构造函数，但是您的代码将被强制使用其中一个重载，以便在创建新数据时提供一些最低级别的数据。
您可能不需要IComparable。这通常用于更复杂的比较，例如多个或复杂的属性。一个例子是纸箱或盒子：
If (width = Other.Width) AndAlso (height = Other.Height) Then
Return 0
ElseIf (width = Other.Height) AndAlso (height = Other.Width) Then
Return 0
End If
还有更多的旋转来解决这个问题，而不是＆＃34;更少＆＃34;比另一个。你不需要它的一个原因是因为If Art1.Postion > Art2.Postion是微不足道的。 你的案例中的另一个原因是因为Dictionary无法排序。
而不是Dictionary，内部列表可以更好地处理您描述的某些内容，但仍然允许您将表示为 Dictionary到一定程度你需要它。为此，我可以使用ICollection<T>：
Public Class ArticleCollection
Implements ICollection(Of Article)
在该行之后按Enter键将添加所有必需的方法，包括：
Public Sub Add(item As Article) Implements ICollection(Of Article).Add
Public Sub Clear() Implements ICollection(Of Article).Clear
Public Function Contains(item As Article) As Boolean Implements ICollection(Of Article).Contains
Public ReadOnly Property Count As Integer Implements ICollection(Of Article).Count
Public Function Remove(item As Article) As Boolean Implements ICollection(Of Article).Remove
完全取决于 这些是如何实现的。它也不排除添加RemoveAt(int32)或RemoveByKey(string)等方法，具体取决于您的需求/使用方式。 ICollection(Of T)的一个好处是它包含IEnumerable，允许每个循环使用（一旦你编写枚举器）：For Each art In Articles
要模拟字典，只允许一个具有特定属性值的项目：
Public Class ArticleCollection
Implements ICollection(Of Article)
Private mcol As List(Of Article)
...
Public Sub Add(item As Article) Implements ICollection(Of Article).Add
' check for existing key
If KeyExists(item.Key) = False Then
mcol.Add(item)
End If
End Sub
你也可以重载它们：
' overload to match Article ctor overload
Public Sub Add(key As String, name As String)
If KeyExists(key) = False Then
' let collection create the new item
' with the minimum required info
mcol.Add(New Article(key, name))
End If
End Sub
如果添加Item属性，则可以对集合（Articles(3)）编制索引：
Property Item(ndx As Int32) As Article
Get
If ndx > 0 AndAlso ndx < mcol.Count Then
Return mcol(ndx)
Else
Return Nothing
End If
End Get
Set(value As Article)
If ndx > 0 AndAlso ndx < mcol.Count Then
mcol(ndx) = value
End If
End Set
End Property
' overload for item by key:
Public Property Item(key As String) As Article
如果集合将显示在标准NET Add中，则Item方法和CollectionEditor属性将非常重要。
有几种方法可以实现排序。最简单的方法是在使用您的集合的代码中使用linq：
Articles = New ArticleCollection
' add Article items
Dim ArticlesByDate = Articles.OrderBy(Function(s) s.PubDate).ToList()
其中PubDate是我添加的Article属性之一。处理排序的另一种方法是通过集合类返回一个新集合（但它很简单，几乎不需要它）：
Friend Function GetSortedList(bSortAsc As Boolean) As List(Of Article)
If bSortAsc Then
Return mcol.OrderBy(Function(q) q.PubDate).
ThenBy(Function(j) j.Position).ToList()
Else
Return mcol.OrderByDescending(Function(q) q.PubDate).
ThenByDescending(Function(j) j.Position).ToList()
End If
End Function
它是否实现ICollection(Of T)，继承自ICollection(Of T)还是继承Dictionary完全取决于它是什么，如何使用以及有什么规则和限制（包括它将被序列化，如何）。这些不是我们所知道的。
MSDN上有一篇关于 Guidelines for Collections 的文章优秀。