Question

I am having a treeview in my wpf application which dynamically binds data from my viewmodel.

<TreeView Grid.Column="0"
          Grid.Row="0"
          ItemsSource="{Binding Main}"
          HorizontalAlignment="Stretch"
          Name="treeView1"
          VerticalAlignment="Stretch"
          Height="auto"
          Width="auto"
          SelectedItemChanged="treeView1_SelectedItemChanged"
          HorizontalContentAlignment="Stretch"
          VerticalContentAlignment="Top"
          Margin="0,0,5,5">
  <TreeView.ItemContainerStyle>
    <Style TargetType="{x:Type TreeViewItem}">
      <Setter Property="IsExpanded"
              Value="{Binding IsExpanded, Mode=TwoWay}" />
      <Setter Property="IsSelected"
              Value="{Binding IsSelected, Mode=TwoWay}" />
      <Setter Property="FontWeight"
              Value="Normal" />
      <Style.Triggers>
        <Trigger Property="IsSelected"
                 Value="True">
          <Setter Property="FontWeight"
                  Value="Bold" />
        </Trigger>
      </Style.Triggers>
    </Style>
  </TreeView.ItemContainerStyle>
  <TreeView.Resources>
    <HierarchicalDataTemplate DataType="{x:Type local:MViewModel}"
                              ItemsSource="{Binding Children}">
      <StackPanel Orientation="Horizontal">
        <TextBlock Text="{Binding Mname}" />
      </StackPanel>
    </HierarchicalDataTemplate>
    <HierarchicalDataTemplate DataType="{x:Type local:FViewModel}"
                              ItemsSource="{Binding Children}">
      <StackPanel Orientation="Horizontal">
        <TextBlock Text="{Binding FName}" />
      </StackPanel>
    </HierarchicalDataTemplate>
    <HierarchicalDataTemplate DataType="{x:Type local:CViewModel}"
                              ItemsSource="{Binding Children}">
      <StackPanel Orientation="Horizontal">
        <TextBlock Text="{Binding Com}" />
      </StackPanel>
    </HierarchicalDataTemplate>
    <DataTemplate DataType="{x:Type local:LViewModel}">
      <StackPanel Orientation="Horizontal">
        <TextBlock Text="{Binding Lo}" />
      </StackPanel>
    </DataTemplate>
  </TreeView.Resources>
</TreeView>

I need to add the header to the whole treeview say “Family” whose childs are the above treeview elements.
How can i add header to the whole treeview.so that when i click that header it should display all Mname and so on.
Please help me with this issue.

Edit:

i have used

  <HierarchicalDataTemplate  DataType="{x:Type TextBlock}" ItemsSource="{Binding Children}">
                        <StackPanel Orientation="Horizontal">
                            <TextBlock Text="Family" />
                        </StackPanel>
  </HierarchicalDataTemplate>

in my TreeviewResource. But still i can’t assign the parent for the tree.

Edit 2:

<TreeView>
   <TreeViewItem ItemsSource="{Binding Main}" Header="Family">
      <TreeViewItemContainerStyle>
      //..
      </TreeViewItemContainerStyle>
      <TreeView.Resources>
      //..
      </TreeView.Resources>
   </TreeViewItem>
</TreeView>

Its showing error.

But when i do like below,

<TreeView>
       <TreeViewItemContainerStyle>
      //..
      </TreeViewItemContainerStyle>
      <TreeView.Resources>
      //..
      </TreeView.Resources>
   <TreeViewItem ItemsSource="{Binding Main}" Header="Family"/>
</TreeView>

The root item has been set. But Only the first set of child are displayed. Childs of child elements are not displaying.

Answer 1

You can wrap your TreeView with Expander element:

<Expander Header="Family">
    <TreeView>
        ...
    <TreeView>
</Expander>

But it is not clear from your question which element you want to use as a Header.

Edit:

So, if you need a root element for a tree, you can add it explicitly in xaml:

<TreeView> <!--ItemsSource you should set on a TreeViewItem-->
    <TreeViewItem ItemsSource="{Binding Main}" Header="Family">
        <TreeViewItem.ItemContainerStyle>
            ...
        </TreeViewItem.ItemContainerStyle>
        <TreeViewItem.Resources>
            ...
        </TreeViewItem.Resources>         
    </TreeViewItem>
<TreeView>