How to customize Group Header in DataGrid Grouping?

I have a DataGrid that looks something like this.

I have grouped data by Gen开发者_JAVA百科der. My GroupItem style is

<Style TargetType="{x:Type GroupItem}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type GroupItem}">
                    <Expander x:Name="exp" IsExpanded="True"
                      Background="White"
                      Foreground="Black">
                        <Expander.Header>
                            <TextBlock Text="{Binding Name}"/>
                        </Expander.Header>
                        <ItemsPresenter />
                    </Expander>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

I want my Group Header 'Male' and 'Female' to look like 'Gender : Male' and 'Gender : Female' instead of simple plain 'Male' and 'Female'. How can I modify my GroupItem style to achieve this so that every time I group my data in datagrid the group header can appear like GroupHeaderTitle : GroupHeaderValue? or Do I need to change anything other than GroupItem style to achieve this?

You can add a property GroupTitle which represents the desired group title at your view model if you are using MVVM or to your Window code-behind otherwise, then add another TextBlock at the Expander.Header which is bound to the GroupTitle property, see the following code snippet:

<Style TargetType="{x:Type GroupItem}">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type GroupItem}">
                <Expander x:Name="exp" IsExpanded="True"
                            Background="White" Foreground="Black">
                    <Expander.Header>
                        <StackPanel Orientation="Horizontal">
                            <TextBlock Text="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=Window}, Path=DataContext.GroupTitle}"/>
                            <TextBlock Text="{Binding Name}"/>
                        </StackPanel>
                    </Expander.Header>
                    <ItemsPresenter />
                </Expander>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

When you add the grouping just supply a converter:

// Get the default view
ICollectionView view = CollectionViewSource.GetDefaultView(...);

// Do the grouping
view.GroupDescriptions.Clear();
view.GroupDescriptions.Add(new PropertyGroupDescription("Gender", new GenderConverter()));

// The converter 
public class GenderConverter : IValueConverter
{
    public object Convert(object value,
    Type targetType, object parameter, CultureInfo culture)
    {
        return string.Format("Gender: {0}", value);
    }

    public object ConvertBack(object value,
    Type targetType, object parameter, CultureInfo culture)
    {
        return DependencyProperty.UnsetValue;
    }
}