GroupStyle.HeaderTemplate Propriedade

Definição

Namespace:

System.Windows.Controls

Assembly:

PresentationFramework.dll

Obtém ou define o modelo usado para exibir o cabeçalho do grupo.

public:
 property System::Windows::DataTemplate ^ HeaderTemplate { System::Windows::DataTemplate ^ get(); void set(System::Windows::DataTemplate ^ value); };

public System.Windows.DataTemplate HeaderTemplate { get; set; }

member this.HeaderTemplate : System.Windows.DataTemplate with get, set

Public Property HeaderTemplate As DataTemplate

Valor da propriedade

DataTemplate

Um objeto DataTemplate usado para exibir o cabeçalho do grupo. O padrão é null.

Exemplos

Os exemplos a seguir mostram um ItemsControl associado a um XmlDataProvider e ao conteúdo code-behind que contém a lógica para adicionar e remover o agrupamento. Quando a caixa de seleção é marcada, o conteúdo do ItemsControl é agrupado pelo atributo Type.

Cada grupo é do tipo CollectionViewGroup. O GroupStyleHeaderTemplate é especificado para que ele apareça como um TextBlock que exibe a Name de cada um dos grupos. Nesse caso, o Name é Work ou Home.

<Window x:Class="GroupingSample.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Grouping Sample"
    Width="220" Height="550">
  <StackPanel>

    <StackPanel.Resources>
      <XmlDataProvider x:Key="myTasks" XPath="Tasks/Task">
        <x:XData>
          <Tasks xmlns="">
            <Task Name="Groceries" Priority="2" Type="Home">
              <Description>Pick up Groceries and Detergent</Description>
            </Task>
            <Task Name="Laundry" Priority="2" Type="Home">
              <Description>Do Laundry</Description>
            </Task>
            <Task Name="Email" Priority="1" Type="Work">
              <Description>Email Clients</Description>
            </Task>
            <Task Name="Clean" Priority="3" Type="Work">
              <Description>Clean my office</Description>
            </Task>
            <Task Name="Dinner" Priority="1" Type="Home">
              <Description>Get ready for family reunion</Description>
            </Task>
            <Task Name="Proposals" Priority="2" Type="Work">
              <Description>Review new budget proposals</Description>
            </Task>
          </Tasks>
        </x:XData>
      </XmlDataProvider>
    </StackPanel.Resources>

    <TextBlock Margin="12,5,5,0" FontSize="20" Text="My Task List"/>
    <CheckBox Margin="10,5,5,10" Checked="AddGrouping"
              Unchecked="RemoveGrouping">Group by task type</CheckBox>
    <ItemsControl Margin="10" Name="myItemsControl"
                  ItemsSource="{Binding Source={StaticResource myTasks}}">
      <ItemsControl.ItemTemplate>
        <DataTemplate>
          <DataTemplate.Resources>
            <Style TargetType="TextBlock">
              <Setter Property="FontSize" Value="18"/>
              <Setter Property="HorizontalAlignment" Value="Center"/>
            </Style>
          </DataTemplate.Resources>
          <Grid>
            <Ellipse Fill="Silver"/>
            <StackPanel>
              <TextBlock Margin="3,3,3,0"
                         Text="{Binding XPath=@Name}"/>
              <TextBlock Margin="3,0,3,7"
                         Text="{Binding XPath=@Priority}"/>
            </StackPanel>
          </Grid>
        </DataTemplate>
      </ItemsControl.ItemTemplate>
      <ItemsControl.ItemContainerStyle>
        <Style>
          <Setter Property="Control.Width" Value="100"/>
          <Setter Property="Control.Margin" Value="5"/>
        </Style>
      </ItemsControl.ItemContainerStyle>
      <ItemsControl.GroupStyle>
        <GroupStyle>
          <GroupStyle.HeaderTemplate>
            <DataTemplate>
              <TextBlock FontWeight="Bold" FontSize="15"
                         Text="{Binding Path=Name}"/>
            </DataTemplate>
          </GroupStyle.HeaderTemplate>
        </GroupStyle>
      </ItemsControl.GroupStyle>
    </ItemsControl>
  </StackPanel>
</Window>

using System;
using System.Windows;
using System.Windows.Data;

namespace GroupingSample
{
    public partial class Window1 : System.Windows.Window
    {

        public Window1()
        {
            InitializeComponent();
        }

        CollectionView myView;
        private void AddGrouping(object sender, RoutedEventArgs e)
        {
            myView = (CollectionView)CollectionViewSource.GetDefaultView(myItemsControl.ItemsSource);
            if (myView.CanGroup == true)
            {
                PropertyGroupDescription groupDescription
                    = new PropertyGroupDescription("@Type");
                myView.GroupDescriptions.Add(groupDescription);
            }
            else
            {
                return;
            }
        }

        private void RemoveGrouping(object sender, RoutedEventArgs e)
        {
            myView = (CollectionView)CollectionViewSource.GetDefaultView(myItemsControl.ItemsSource);
            myView.GroupDescriptions.Clear();
        }
    }
}

Imports System.Windows
Imports System.Windows.Data

Namespace GroupingSample
    Partial Public Class Window1
        Inherits System.Windows.Window

        Public Sub New()
            InitializeComponent()
        End Sub

        Private myView As CollectionView
        Private Sub AddGrouping(ByVal sender As Object, ByVal e As RoutedEventArgs)
            myView = CType(CollectionViewSource.GetDefaultView(myItemsControl.ItemsSource), CollectionView)
            If myView.CanGroup = True Then
                Dim groupDescription As New PropertyGroupDescription("@Type")
                myView.GroupDescriptions.Add(groupDescription)
            Else
                Return
            End If
        End Sub

        Private Sub RemoveGrouping(ByVal sender As Object, ByVal e As RoutedEventArgs)
            myView = CType(CollectionViewSource.GetDefaultView(myItemsControl.ItemsSource), CollectionView)
            myView.GroupDescriptions.Clear()
        End Sub
    End Class
End Namespace

O exemplo a seguir mostra como usar a propriedade HeaderTemplate:

<ListBox Name="Master" Grid.Row="2" Grid.ColumnSpan="3" Margin="8"
    ItemsSource="{Binding Source={StaticResource listingDataView}}">
    <ListBox.GroupStyle>
        <GroupStyle 
          HeaderTemplate="{StaticResource groupingHeaderTemplate}"
          />
    </ListBox.GroupStyle>
</ListBox>

A seguir está a definição do groupingHeaderTemplateDataTemplate:

<DataTemplate x:Key="groupingHeaderTemplate">
    <TextBlock Text="{Binding Path=Name}"
               Foreground="Navy" FontWeight="Bold" FontSize="12"/>
</DataTemplate>

Para obter o exemplo completo, consultede demonstração de associação de dados .

Confira também

• HeaderTemplateSelector