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WPF Expander.Header horizontal extension

I have an extender in Wpf. In the header, I have a shortcut to the left aligned and you want to have a button on the correct site. I am using the following XAML:

<Expander HorizontalAlignment="Stretch" IsExpanded="True">
    <Expander.Header >
        <Grid HorizontalAlignment="Stretch" Background="Aqua" Margin="0">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*"/>
                <ColumnDefinition Width="Auto" />
            </Grid.ColumnDefinitions>
            <Label Grid.Column="0" Content="Label on the left site"/>
            <Button Grid.Column="1" Content="Button on the right"/>
         </Grid>
    </Expander.Header>
    <Label Content="Some Content"/>
</Expander>

But that does not work. The button in the title is aligned to the left next to the label. Can someone explain to me how to do this correctly?

+6
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5 answers

xaml, . HorizontailAlignment - . Unfortunatley , scher ( ActualWidth), , ui , , .) Bolu " Expander" , xaml.

<ItemsControl x:Name="ItemGroups" Grid.Column="2" Grid.Row="0"   ItemsSource="{Binding Model.ItemGroups}" ScrollViewer.VerticalScrollBarVisibility="Auto" >
            <ItemsControl.ItemTemplate>
                <DataTemplate>
                    <Expander Margin="4,0"   Header="{Binding}">
                        <Expander.HeaderTemplate>
                            <DataTemplate>
                                <Grid  HorizontalAlignment="{Binding Path=HorizontalAlignment, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ContentPresenter}}, Mode=OneWayToSource}" >
                                    <Grid.ColumnDefinitions>
                                        <ColumnDefinition   />
                                        <ColumnDefinition  Width="Auto"/>
                                        <ColumnDefinition  Width="64"/>
                                    </Grid.ColumnDefinitions>

                                    <TextBox Grid.Column="0"  Text="{Binding Name, Mode=TwoWay}" />
                                    <TextBlock Grid.Column="1" Text="{Binding TotalCostString}" Margin="4,0"/>
                                    <Button Grid.Column="2" Command="{Binding DataContext.RemoveItemGroup, ElementName=ItemGroups, Mode=OneWay}" CommandParameter="{Binding}" Content="Remove"/>
                                </Grid>         
                            </DataTemplate>
                        </Expander.HeaderTemplate>
                        <Expander.Content>
                            <TextBlock Text="{Binding Summary}"></TextBlock>
                        </Expander.Content>
                    </Expander>
                </DataTemplate>
            </ItemsControl.ItemTemplate>
        </ItemsControl>
+15

Expander Left.

Stretch, OneWayToSource HorizontalAlignment ( Stretch Grid), :

<Expander>
    <Expander.Header>
        <Grid Background="Yellow">
            <TextBlock Text="Header"
                       HorizontalAlignment="{Binding HorizontalAlignment, RelativeSource={RelativeSource AncestorType=ContentPresenter}, Mode=OneWayToSource}" />
        </Grid>
    </Expander.Header>
</Expander>

..: , , , .

+7

I took one of the solutions related to Bol. This is the result:

    <Expander HorizontalAlignment="Stretch" IsExpanded="True">
        <Expander.Header >
            <!-- Width-Binding is needed, to fill the whole header horizontally-->
            <Grid HorizontalAlignment="Stretch" Background="Aqua" Margin="0" Width="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Expander}}, Path=ActualWidth}">
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="*"/>
                    <ColumnDefinition Width="Auto" />
                </Grid.ColumnDefinitions>
                <Label Grid.Column="0" Content="Label on the left site"/>
                <!-- Margin is needed, to bring the Button into the view -->
                <Button Grid.Column="1" Content="Button on the right" Margin="0,0,40,0"/>
            </Grid>
        </Expander.Header>
        <Label Content="Some Content"/>
    </Expander>
+3
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* Heck: right indent, e.g. 100000: Padding="2 2 100000 2"

<Expander Name="Name" ExpandDirection="Down">
    <Expander.Header>
        <TextBlock Text="Expander..." Margin="0 5" Padding="2 2 100000 2" />
    </Expander.Header>
</Expander>
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If you do not want to change the appearance of the expander header at all, you can also use the behavior (System.Windows.Interactivity), which changes the horizontal alignment when loading the header

internal class StretchingExpanderHeaderBehavior : Behavior<Expander>
{
    protected override void OnAttached()
    {
        AssociatedObject.Loaded += StretchHeader;
    }

    private void StretchHeader(object sender, RoutedEventArgs e)
    {
        DependencyObject header = AssociatedObject.Header as DependencyObject;
        if (header != null)
        {
            ContentPresenter contentPresenter = VisualTreeHelper.GetParent(header) as ContentPresenter;
            if (contentPresenter != null)
            {
                contentPresenter.HorizontalAlignment = HorizontalAlignment.Stretch;
            }
        }
    }
}

It can be attached to the expander

<Expander>
    <Expander.Header>
        <DockPanel HorizontalAlignment="Stretch">
            <Button DockPanel.Dock="Right" Content="Button on the right" />
            <Label Content="Label on the left site"/>
        </DockPanel>
    </Expander.Header>

    <Border BorderBrush="LightGray" BorderThickness="1">
        <ItemsPresenter />
    </Border>

    <iy:Interaction.Behaviors>
        <bhv:StretchingExpanderHeaderBehavior />
    </iy:Interaction.Behaviors>

</Expander>
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