Public Enum Entwicklung
    Positiv
    Negativ
    Stagnation
End Enum
 
Public Class TestClass
 
    Private mName As String
    Private mEntwicklung As Entwicklung
 
    Public Property Name() As String
        Get
            Return Me.mName
        End Get
        Set(ByVal value As String)
            Me.mName = value
        End Set
    End Property
    Public Property Entwicklung() As Entwicklung
        Get
            Return Me.mEntwicklung
        End Get
        Set(ByVal value As Entwicklung)
            Me.mEntwicklung = value
        End Set
    End Property
 
    Public Sub New(ByVal name As String, ByVal entw As Entwicklung)
        Me.mName = name
        Me.mEntwicklung = entw
    End Sub
 
End Class

Class Window1
    Private mTestList As List(Of TestClass)
 
    Public Sub New()
        InitializeComponent()
 
        Me.mTestList = New List(Of TestClass)
        Me.mTestList.Add(New TestClass("Name1", Entwicklung.Positiv))
        Me.mTestList.Add(New TestClass("Name2", Entwicklung.Negativ))
        Me.mTestList.Add(New TestClass("Name3", Entwicklung.Stagnation))
 
        Me.ListView1.DisplayMemberPath = "Name"
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.Windows.RoutedEventArgs) Handles Button1.Click
        Me.ListView1.ItemsSource = (From t As TestClass In Me.mTestList).ToList
 
        Dim index As Integer = 0
        For Each lvi As ListViewItem In Me.ListView1.Items 'Hier kommt der 
        ' Fehler
            If Me.mTestList(index).Entwicklung = Entwicklung.Positiv Then
                lvi.Background = Brushes.Green
            ElseIf Me.mTestList(index).Entwicklung = Entwicklung.Negativ Then
                lvi.Background = Brushes.Red
            ElseIf Me.mTestList(index).Entwicklung = Entwicklung.Stagnation Then
                lvi.Background = Brushes.LightGray
            End If
            index += 1
        Next
    End Sub
 
End Class