WPF distinguishes between coding-SelectionChanged and mouse-SelectionChanged

Question

I have a question about Machiavell (for me). In my WPF application, I have a ListBox that is in ItemTemplate a Combobox. When the user selects ComboBoxItem, I have to perform some complex operations on the ObservableCollection, which is an ItemSource ListBox, then I have to show the ListBox with the changed data. The problem is that if I handle the "SelectionChanged" event of the ComboBox control, every time I change the source class of comboboxItems, I enter the method that handles the event, and this produces incorrect results. In short, I have to somehow distinguish between SelectionChanged, the generated code, and SelectionChanged, created manually by the user with the mouse. I tried many ways, but nothing works: - (

The Soution I thought was the best was to handle the "GotFocus" or "MouseUp" ContentPresenter event of the ItemContainerStyle Combo element, or to handle the same events ("GotFocus" and "MouseUp") the ItemsPanel Combo, but the method I processed did not capture the event ( during debugging, the cursor does not enter at all in the method).

I cannot use a boolean to stop the "SelectionChanged" method until the "first round" is complete, because changes to the original ComboBoxItems class occur after this method has been executed.

The default value of Combos is not always the first (it would be too simple :-)), and it is not always the same. Each time a user selects an element from one of Combo, the default value for other Combos should change.

? Pileggi

' XAML
<Style x:Key="modComboCriteriEventParts" TargetType="{x:Type ComboBox}">
    <EventSetter Event="Selector.SelectionChanged" Handler="cb_SelectionChanged"/>
</Style>

<DataTemplate x:Key="modLBoxCriteriParts">
    <ComboBox Style = "{StaticResource modComboCriteriEventParts}"
        ItemsSource = "{Binding CriteriItemList}"
        ItemContainerStyle = "{DynamicResource modComboContainerParts}"
        SelectedIndex = "{Binding valueSelected}" ... />
</DataTemplate>

<ListBox x:Name="lbCriteri" IsSynchronizedWithCurrentItem="True"
    ItemsSource = "{Binding CriteriList, Source={StaticResource P_CriteriDataSource}}"
    ItemTemplate = "{DynamicResource modLBoxCriteriParts}"
    ... />


' Code Behind
Private Sub cb_SelectionChanged(ByVal sender As System.Object, ByVal e As SelectionChangedEventArgs)
    Dim ri as New RicambiCriteriList() As ObservableCollection(Of P_CriteriItem)

    ' some complex operations with ri ...

    be = BindingOperations.GetBindingExpression(Me.lbCriteri, ListBox.ItemsSourceProperty)
    Dim allCriteri As P_Criteri = DirectCast(be.DataItem, P_Criteri)
    allCriteri.AddData (ri)

    e.Handled = True
End Sub


' Source-Class
Public Class P_Criteri

    Private _CriteriList As New ObservableCollection(Of P_CriteriItem)

    Public ReadOnly Property CriteriList() As ObservableCollection(Of P_CriteriItem)
        Get
            CriteriList = _CriteriList
        End Get
    End Property

    Public Sub AddData(ByVal CriteriListPass As ObservableCollection(Of P_CriteriItem))
        _CriteriList.Clear()
        For Each a As P_CriteriItem In CriteriListPass
            _CriteriList.Add(a)
        Next
    End Sub
End Class

Public Class P_CriteriItem
    Implements INotifyPropertyChanged

    Public Sub New(ByVal criterioPass As String, ByVal CriteriItemListPass As ObservableCollection(Of P_CriteriItemValore), _
        ByVal widthCriteriValuesPass As Double)

        Me._criterio = criterioPass
        Me._CriteriItemList = CriteriItemListPass
        Me._widthCriteriValues = widthCriteriValuesPass
    End Sub

    Private _criterio As String = ""
    Private _CriteriItemList As New ObservableCollection(Of P_CriteriItemValore)

    Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged

    Public Property criterio() As String
        Get
            Return Me._criterio
        End Get
        Set(ByVal value As String)
            If Not Object.Equals(Me._criterio, value) Then
                Me._criterio = value
                Me.OnPropertyChanged ("criterio")
            End If
        End Set
    End Property

    Public Property CriteriItemList() As ObservableCollection(Of P_CriteriItemValore)
        Get
            Return Me._CriteriItemList
        End Get
        Set(ByVal value As ObservableCollection(Of P_CriteriItemValore))
            If Not Object.Equals(Me._CriteriItemList, value) Then
                Me._CriteriItemList = value
                Me.OnPropertyChanged ("CriteriItemList")
            End If
        End Set
    End Property

    Protected Overridable Sub OnPropertyChanged(ByVal propertyName As String)
        Dim handler As PropertyChangedEventHandler = Me.PropertyChangedEvent
        If handler IsNot Nothing Then
            RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(propertyName))
        End If
    End Sub
End Class

Public Class P_CriteriItemValore
    Implements INotifyPropertyChanged

    Public Sub New(ByVal criterioValorePass As String)
        Me._criterioValore = criterioValorePass
    End Sub

    Private _criterioValore As String = Nothing

    Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged

    Public Property criterioValore() As String
        Get
            Return Me._criterioValore
        End Get
        Set(ByVal value As String)
            If Not Object.Equals(Me._criterioValore, value) Then
                Me._criterioValore = value
                Me.OnPropertyChanged ("criterioValore")
            End If
        End Set
    End Property

    Protected Overridable Sub OnPropertyChanged(ByVal propertyName As String)
        Dim handler As PropertyChangedEventHandler = Me.PropertyChangedEvent
        If handler IsNot Nothing Then
            RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(propertyName))
        End If
    End Sub
End Class

Answer 1

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, MouseDown/GotFocus, PreviewMouseDown/PreviewGotFocus. , , , wpf .