Silverlight - TreeView和HierarchialDataTemplate

Question

原谅我的英语不好，我希望能够解释清楚。 我在Treview（SL4）中看不到子节点。 我有这种情况：

2个班级：

Public Class My_Root
    Private My_Cod_Prod As String
    Public Property Cod_Prod() As String
        Get
            Return My_Cod_Prod
        End Get
        Set(ByVal value As String)
            My_Cod_Prod = value
        End Set
    End Property

    Private My_Desc_Prod As String
    Public Property Desc_Prod() As String
        Get
            Return My_Desc_Prod
        End Get
        Set(ByVal value As String)
            My_Desc_Prod = value
        End Set
    End Property

    Private My_Cod_Desc_Prod As String
    Public Property Cod_Desc_Prod() As String
        Get
            Return My_Cod_Desc_Prod
        End Get
        Set(ByVal value As String)
            My_Cod_Desc_Prod = value
        End Set
    End Property

    Private My_Items As New My_Child
    Public Property Items() As My_Child
        Get
            Return My_Items
        End Get
        Set(ByVal value As My_Child)
            My_Items = value
        End Set
    End Property


End Class



Public Class My_Child
    Implements INotifyPropertyChanged
    Dim Selezionato As Boolean = False
    Private My_Cod_PosFis As String
    Public Property Cod_PosFis() As String
        Get
            Return My_Cod_PosFis
        End Get
        Set(ByVal value As String)
            My_Cod_PosFis = value
        End Set
    End Property
    Private My_Desc_PosFis As String
    Public Property Desc_PosFis() As String
        Get
            Return My_Desc_PosFis
        End Get
        Set(ByVal value As String)
            My_Desc_PosFis = value
        End Set
    End Property

    Public Property Selezione
        Get
            Return Selezionato
        End Get
        Set(ByVal value)
            Selezionato = value
            NotifyPropertyChanged("Selezione")
        End Set
    End Property

    Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged
    Public Sub NotifyPropertyChanged(ByVal propertyName As String)
        RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(propertyName))
    End Sub


End Class

然后我创建一个ObservableCollection：

Public Shared nodi As New ObservableCollection(Of My_Root)()

以这种方式表达的人：

 Private Sub Compila_Class_My_Root()
   For Each Prod In Elenco_ASS_Prodotti_PosFiscali
                Dim NodoRoot As New My_Root

                    NodoRoot.Cod_Prod = Prod.PFIS_CODPROD
                    NodoRoot.Desc_Prod = Prod.PFIS_DESCOM
                    NodoRoot.Cod_Desc_Prod = Prod.PFIS_CODPROD & " - " & Prod.PFIS_DESCOM
                 Dim NodoChild As New My_Child
                    NodoChild.Cod_PosFis = Prod.PFIS_POSFIS
                    Dim desc_pos_fis As String = get_DescrizionePosFis(Prod.PFIS_POSFIS)
                    NodoChild.Desc_PosFis = desc_pos_fis
                    NodoRoot.Items = NodoChild
                nodi.Add(NodoRoot)
   Next

     MyTreeView.ItemsSource = nodi 

End Sub

这是XAML到HierarchicalDataTemplate：

       <sdk:HierarchicalDataTemplate x:Key="MyNodeRoot">
            <sdk:HierarchicalDataTemplate.ItemsSource>
                <Binding Path="My_Root" />
            </sdk:HierarchicalDataTemplate.ItemsSource>
            <TextBlock Text="{Binding Path=Cod_Desc_Prod}" />
        </sdk:HierarchicalDataTemplate>

      <sdk:TreeView Name="MyTreeView"  ItemTemplate="{StaticResource MyNodeRoot}"/>

在这里，我无法理解如何显示子节点。

Answer 1

我不是VB专家，但看起来你的Items属性不是数组。我认为需要声明如下。

Public Property Items() As My_Child()

然后，在Compila_Class_My_Root方法中，设置NodoRoot.Items时，也在这里使用数组：

Dim children As My_Child() = { NodoChild }
NodoRoot.Items = children

在您的XAML中，HierarchicalDataTemplate的数据上下文是My_Root实例，这就是您可以绑定到My_Root（Cod_Desc_Prod）的属性的原因。 ItemsSource也应该绑定到My_Root的属性：

<Binding Path="Items" />

或者，您可以使用较不详细的语法：

   <sdk:HierarchicalDataTemplate x:Key="MyNodeRoot" ItemsSource="{Binding Items}">
        <TextBlock Text="{Binding Cod_Desc_Prod}" />
    </sdk:HierarchicalDataTemplate>

最后，您需要指定儿童的外观。

<DataTemplate x:Key="MyChildTemplate">
    <StackPanel Orientation="Horizontal">
        <CheckBox IsChecked="{Binding Selezione, Mode=TwoWay}" />
        <TextBlock Text="{Binding Desc_PosFis}" />
        <!-- Or whatever you want here... -->
    </StackPanel>
</DataTemplate>

<sdk:HierarchicalDataTemplate x:Key="MyNodeRoot"
    ItemsSource="{Binding Items}"
    ItemTemplate="{StaticResource MyChildTemplate}"
    >
    <TextBlock Text="{Binding Cod_Desc_Prod}" />
</sdk:HierarchicalDataTemplate>

Answer 2

非常感谢安德鲁，我解决了这个问题（尽管它不是一个非常漂亮的解决方案）可能对某些人有用）：

我参加了课程：My_Child

    Public Property Selezione
    Get
        Return Selezionato
    End Get
    Set(ByVal value)
        Selezionato = value
        NotifyPropertyChanged("Selezione")
    End Set
    End Property

并添加到此属性：

     Private My_Cod_Prod As String
    Public Property Cod_Prod() As String
        Get
            Return My_Cod_Prod
        End Get
        Set(ByVal value As String)
            My_Cod_Prod = value
        End Set
    End Property

以这种方式表达的人：我修改了

 Private Sub Compila_Class_My_Root()
    For Each Prod In Elenco_ASS_Prodotti_PosFiscali
            Dim NodoRoot As New My_Root

                NodoRoot.Cod_Prod = Prod.PFIS_CODPROD
                NodoRoot.Desc_Prod = Prod.PFIS_DESCOM
                NodoRoot.Cod_Desc_Prod = Prod.PFIS_CODPROD & " - " & Prod.PFIS_DESCOM
             Dim NodoChild As New My_Child
                NodoChild.Cod_PosFis = Prod.PFIS_POSFIS
                Dim desc_pos_fis As String = get_DescrizionePosFis(Prod.PFIS_POSFIS)
                NodoChild.Desc_PosFis = desc_pos_fis
                NodoChild.Cod_Prod = Prod.PFIS_CODPROD  '******   ADDED   ******'
                NodoRoot.Items = NodoChild
            nodi.Add(NodoRoot)
      Next

   MyTreeView.ItemsSource = nodi 

End Sub

然后在这里我将搜索集合中的项目

    Private Sub MyTreeView_SelectedItemChanged(sender As Object, e As                    System.Windows.RoutedPropertyChangedEventArgs(Of Object)) Handles MyTreeView.SelectedItemChanged
    Dim myTreeView As TreeView = TryCast(sender, TreeView)
    Dim chkele As My_Child
    Dim chkprod As My_Root
    Dim elemento 'elemento selezionato
    Try
        chkele = myTreeView.SelectedItem

    Catch ex As Exception
        chkele = Nothing
    End Try
    If chkele Is Nothing Then
        '    ho selezionato il prodotto
        chkprod = myTreeView.SelectedItem
    End If


     Try
       elemento = (From ele In Elenco_ASS_Prodotti_PosFiscali Where ele.PFIS_CODPROD = chkele.Cod_Prod And ele.PFIS_POSFIS = chkele.Cod_PosFis).Single
    Catch ex As Exception

    End Try

    End Sub