在TreeView中顯示「根」節點

Question

如何在TreeView中顯示「根」？

我是否需要爲根創建一個特殊的HierarchicalDataTemplate？

這是我的代碼：

<TreeView Margin="0,0,15,0" Name="treeView1" ItemsSource="{Binding Path=Children}">   
    <TreeView.Resources>   
    <HierarchicalDataTemplate DataType="{x:Type local:Node}" 
           ItemsSource="{Binding Path=Children}"> 
     <Border BorderBrush="Black" BorderThickness="1"> 
     <StackPanel> 
      <TextBlock Margin="10,0,0,0" Text="{Binding Data}"/> 
     </StackPanel> 
     </Border> 
    </HierarchicalDataTemplate> 
    </TreeView.Resources> 
</TreeView> 

Node node0 = new Node("Root"); 
Node node1 = new Node("Node1-1"); 
Node node12 = new Node("Node1-2"); 
Node node21 = new Node("Node2-1"); 
Node node22 = new Node("Node2-2"); 
Node node31 = new Node("Node3-1"); 
Node node9 = new Node("Node9"); 
node12.Children.Add(node21); 
node12.Children.Add(node22); 
node22.Children.Add(node31); 
node1.Children.Add(node9); 

node0.Children.Add(node1); 
node0.Children.Add(node12); 
treeView1.DataContext = node0; 

public class Node 
{  
    List<Node> children; 
    public List<Node> Children 
    { 
     get { return children; } 
     set { children = value; } 
    }  

    string data; 
    public string Data 
    { 
     get { return data; } 
     set { data = value; } 
    } 

    public Node() 
    { 
     children = new List<Node>(); 
    } 

    public Node(string data) 
     : this() 
    { 
     this.data = data; 
    } 

} 

Answer 1

如果你想你需要與中只有一個項目指定ItemsSource根，根結點，它必須是一個IEnumerable，節點本身不可能是源頭。

例如

treeView.ItemsSource = new [] { rootNode }; 

Answer 2

使用轉換器：

public class RootTreeviewConverter : IValueConverter 
{ 
    public object Convert(object value, Type targetType, 
     object parameter, System.Globalization.CultureInfo culture) 
    { 
     if (value == null) 
      return null; 

     return new object[] { value }; 
    } 

    public object ConvertBack(object value, Type targetType, 
     object parameter, System.Globalization.CultureInfo culture) 
    { 
     throw new NotImplementedException(); 
    } 
} 

在XAML：

<TreeView ItemsSource="{Binding Path=RootNode,Converter={StaticResource rootConv}}" />