WPF樹視圖與多種類型的子節點

Question

我有一個TreeView說我綁定到一個觀察的集合，它有它內部的兩個可觀察集合：

Public Class ocSpecialPolicies 
    Implements INotifyPropertyChanged 
    Public Event PropertyChanged(sender As Object, e As System.ComponentModel.PropertyChangedEventArgs) Implements System.ComponentModel.INotifyPropertyChanged.PropertyChanged 
    Protected Overridable Sub OnPropertyChanged(ByVal Propertyname As String) 
     If Not Propertyname.Contains("Changed") Then 
      Changed = True 
     End If 
     RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(Propertyname)) 
    End Sub 

    Private _changed As Boolean 
    Public Property Changed() As Boolean 
     Get 
      Return _changed 
     End Get 
     Set(ByVal value As Boolean) 
      If _changed <> value Then 
       _changed = value 
       OnPropertyChanged("Changed") 
      End If 
     End Set 
    End Property 

    Public Property Items As New ObservableCollection(Of ocSpecialPoliciesItem) 
    Public Property Explanations As New ObservableCollection(Of ocSpecialPoliciesExplain) 

    Private _RecallNum As String 
    Public Property RecallNum As String 
     Get 
      Return _RecallNum 
     End Get 
     Set(value As String) 
      If _RecallNum <> value Then 
       _RecallNum = value 
       OnPropertyChanged("RecallNum") 
      End If 
     End Set 
    End Property 
End Class 

我有一半的工作：

<TreeView Name="TreeView2" Margin="3" ItemsSource="{Binding ElementName=MainWindow, Path=SpecialPolicies, UpdateSourceTrigger=PropertyChanged}"> 
    <TreeView.ItemTemplate> 
     <HierarchicalDataTemplate ItemsSource="{Binding Path=Items, UpdateSourceTrigger=PropertyChanged}"> 
      <TextBlock Text="{Binding Path=RecallNum}" > 
      </TextBlock> 
      <HierarchicalDataTemplate.ItemTemplate> 
       <DataTemplate> 
        <TextBlock Text="{Binding Path=LaborOp}" > 
        </TextBlock> 
       </DataTemplate> 
      </HierarchicalDataTemplate.ItemTemplate> 
     </HierarchicalDataTemplate> 
    </TreeView.ItemTemplate> 
</TreeView> 

我在哪裏可以看到RecallNum屬性和Items屬性，但我無法弄清楚如何在RecallNum下顯示解釋作爲附加子節點。

理想的情況下，它會是這個樣子：

RecallNum* 
    Items 
     LaborOp 
     LaborOp 
     LaborOp** 
    Explanations 
     *ExplanationText 
     **ExplanationText 

我試過HierarchicalDataTemplate in TreeView.Resources，但我只是沒有做正確的事情。綁定是我一直困難的時刻，我的頭繞過。

Answer 1

我不知道這是否會在環境中工作，而現在我不能嘗試，但怎麼樣......

 <HierarchicalDataTemplate.ItemTemplate> 
      <DataTemplate TargetType="{x:Type=ocSpecialPoliciesItem}"> 
       ... 
      </DataTemplate> 
      <DataTemplate TargetType="{x:Type=ocSpecialPoliciesExplain}"> 
       ... 
      </DataTemplate> 
     </HierarchicalDataTemplate.ItemTemplate> 

或者類似的規定？

編輯： 據瞭解，我們希望有一個TreeView有兩種類型的項目（對不起，這是C＃，但我相信你可以翻譯）。

您可以嘗試製作一個基類，從中派生ocSpecialPoliciesItem和ocSpecialPoliciesExplain，並創建一個可觀察的基類集合。然後在TreeView中使用兩個DataTemplates。

class SpecialPoliciesBase {} 

class ocSpecialPoliciesItem : SpecialPoliciesBase 
{ ... } 

class ocSpecialPoliciesExplain : SpecialPoliciesBase 
{ ... } 

class ocSpecialPolicies 
{ 
    // this is where you put ocSpecialPoliciesItem and 
    // ocSpecialPoliciesExplain 
    // I do not see any code for populating your two collections, 
    // but I suppose you must have some somewhere 
    public ObersvableCollection<SpecialPoliciesBase> SPCollection 
    { get ... } 
} 

而在你XAML

<TreeView 
    Name="TreeView2" 
    Margin="3" 
    ItemsSource="{ 
    Binding ElementName=MainWindow, 
    Path=SPCollection, 
    UpdateSourceTrigger=PropertyChanged}"> 

    <TreeView.ItemTemplate> 
    <HierarchicalDataTemplate ...> 
     <TextBlock Text="{Binding Path=RecallNum}" /> 

     <HierarchicalDataTemplate.ItemTemplate> 
      <DataTemplate TargetType={x:Type ocSpecialPoliciesItem} > 
       <!- this is where you put the template for Item !-> 
      </DataTemplate> 
      <DataTemplate TargetType={x:Type: ocSpecialPoliciesExplain} > 
       <!- this is where you put the template for Explanations !-> 
      </DataTemplate> 
     </HierarchicalDataTemplate.ItemTemplate> 
    </HierarchicalDataTemplate> 
</TreeView.ItemTemplate> 

我有這樣的事情的工作，但不是一個TreeView。我使用了一個空的抽象ViewBase類以及幾個具體的View類。我的ViewModel有一個名爲CurrentView的屬性，類型爲ViewBase，每個具體視圖都有一個DataTemplate。我的XAML爲CurrentView的任何派生類挑選出正確的DataTemplate。