Question

我的列表和排序功能有些问题。我创建了类Variation和Variations。我将Variations类作为我的Variation的集合列表进行交易以将其分开。现在，当我创建集合时，我想按Variation属性位置排序，我得到错误。你能帮我吗？以下所有必要信息。

变异类：

Public Class Variation

    Property ID As Integer
    Property Name As String
    Property Erstellungsdatum As Date
    Property Position As SByte

    Sub New()
    End Sub

    Sub New(id As Integer)
        _ID = id
    End Sub

    Sub New(id As Integer, name As String)
        _ID = id
        _Name = name
    End Sub
    Sub New(name As String, position As Integer)
        _Name = name
        _Position = position
    End Sub

    Sub New(id As Integer, name As String, position As SByte)
        _ID = id
        _Name = name
        _Position = position
    End Sub
    Sub New(id As Integer, name As String, erstellungsdatum As Date)
        _ID = id
        _Name = name
        _Erstellungsdatum = erstellungsdatum
    End Sub

End Class

班级变化：

Public Class Variations
    Implements IDisposable
    Implements IComparer(Of Variation)

    Public MyVariationsCollection As List(Of Variation)

    Sub New()
        MyVariationsCollection = New List(Of Variation)
    End Sub

    Public Function AddToCollection(ByVal variation As Variation) As Boolean
        MyVariationsCollection.Add(variation)
        Return True
    End Function

    Public Sub RemoveFromCollection(index As Integer)
        If Not IsNothing(MyVariationsCollection.Item(index)) Then
            MyVariationsCollection.RemoveAt(index)
        End If
    End Sub


    Public Function Compare(x As Variation, y As Variation) As Integer Implements IComparer(Of Variation).Compare
        If x.Position > y.Position Then
            Return 1
        End If

        If x.Position < y.Position Then
            Return -1
        End If
        Return 0
    End Function

End Class

在我正在做的代码中：

Private variations As New Variations
 variations.AddToCollection(New BusinessLayer.Variation(Id, Name, StartPosition))

现在我想通过例如我在Variations中实现的位置对此列表进行排序，我希望它在那里，而不是在Variation类中，因为我希望交易变化类作为Variation对象的集合分开，如果你知道我是什么的意思。

但是，如果我这样做：

_variations.MyVariationsCollection.Sort()

然后我得到错误：

     ---------------------------
    myprog
    ---------------------------
    System.InvalidOperationException: 
You can not compare two elements in the array. ---> System.ArgumentException: At least one object must implement IComparable element

       w System.Collections.Comparer.Compare(Object a, Object b)

       w System.Collections.Generic.ArraySortHelper`1.SwapIfGreater(T[] keys, IComparer`1 comparer, Int32 a, Int32 b)

       w System.Collections.Generic.ArraySortHelper`1.DepthLimitedQuickSort(T[] keys, Int32 left, Int32 right, IComparer`1 comparer, Int32 depthLimit)

       w System.Collections.Generic.ArraySortHelper`1.Sort(T[] keys, Int32 index, Int32 length, IComparer`1 comparer)

       --- Koniec śladu stosu wyjątków wewnętrznych ---

       w System.Collections.Generic.ArraySortHelper`1.Sort(T[] keys, Int32 index, Int32 length, IComparer`1 comparer)

       w System.Array.Sort[T](T[] array, Int32 index, Int32 length, IComparer`1 comparer)

       w System.Collections.Generic.List`1.Sort(Int32 index, Int32 count, IComparer`1 comparer)

       w Cenea.UserControl1..ctor(Variations variations, Artikel mainArtikel) w C:\Users\Robert\Desktop\Cenea\Cenea\UserControl1.vb:wiersz 26

       w Cenea.FrmMain.btnVariationProcees_Click(Object sender, EventArgs e) w C:\Users\Robert\Desktop\Cenea\Cenea\FrmMain.vb:wiersz 450

       w System.Windows.Forms.Control.OnClick(EventArgs e)

       w DevComponents.DotNetBar.ButtonX.OnClick(EventArgs e)

       w DevComponents.DotNetBar.ButtonX.OnMouseUp(MouseEventArgs e)

       w System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)

       w System.Windows.Forms.Control.WndProc(Message& m)

       w System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

       w System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)

       w System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)

       w System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)

       w System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)

       w Cenea.ProgStart.main() w C:\Users\Robert\Desktop\Cenea\Cenea\ProgStart.vb:wiersz 14
    ---------------------------
    OK   
    ---------------------------

最终解决方案：

Public Class Variation
    Implements IComparable(Of Variation)
...

  Public Function CompareTo(pother As Variation) As Integer Implements IComparable(Of Variation).CompareTo
        Return String.Compare(Me.Position, pother.Position)
    End Function

...

变化：

Imports BusinessLayer

Public Class Variations
    Implements IDisposable

    Public collection As List(Of Variation)

    Sub New()
        collection = New List(Of Variation)
    End Sub

    Public Function AddToCollection(ByVal variation As Variation) As Boolean
        collection.Add(variation)
        Return True
    End Function

    Public Sub RemoveFromCollection(index As Integer)
        If Not IsNothing(collection.Item(index)) Then
            collection.RemoveAt(index)
        End If
    End Sub

    Public Sub SortByPosition()
        collection.Sort()
    End Sub

#Region "IDisposable Support"
    Private disposedValue As Boolean ' To detect redundant calls

    ' IDisposable
    Protected Overridable Sub Dispose(disposing As Boolean)
        If Not Me.disposedValue Then
            If disposing Then
                ' TODO: dispose managed state (managed objects).
            End If

            ' TODO: free unmanaged resources (unmanaged objects) and override Finalize() below.
            ' TODO: set large fields to null.
        End If
        Me.disposedValue = True
    End Sub

    ' This code added by Visual Basic to correctly implement the disposable pattern.
    Public Sub Dispose() Implements IDisposable.Dispose
        ' Do not change this code.  Put cleanup code in Dispose(ByVal disposing As Boolean) above.
        Dispose(True)
        GC.SuppressFinalize(Me)
    End Sub
#End Region

End Class

Answer 1

unlocalized error是“无法比较数组中的两个元素”。实现非通用IComparer。

如documentation Array.Sort中所述，使用非通用IComparer界面：

此界面与Array.Sort和。{ Array.BinarySearch方法。它提供了一种自定义排序的方法集合的顺序。有关参数的说明，请参阅比较方法和返回值。

列表排序实现

1 个答案: