应用ControlTemplate时无法设置GroupBox的标题

Question

I am using the following control template

<ControlTemplate x:Key="CriterionTemplate" Name="CriterionTemplate">    
    <GroupBox Name="CriterionGroupbox">
        <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="20"/>
            <ColumnDefinition Width="50"/>
        </Grid.ColumnDefinitions>

        <Button x:Name="KeywordSelectionButton"  Grid.Column="0" Height="50" IsManipulationEnabled="True" Style="{StaticResource HiddenButtonStyle}">
            <DockPanel HorizontalAlignment="Left" Width="{TemplateBinding ActualWidth}">
            <Image Name="SelectionImage" HorizontalAlignment="Left" Height="50"/>
            <Label Name="SelectionLabel" HorizontalAlignment="Left" VerticalAlignment="Center" FontSize="11" FontFamily="Comic Sans MS"/>
            </DockPanel>
        </Button>
        <Button x:Name="ClearButton"  Grid.Column="2" Height="50"/>
        </Grid>
    </GroupBox>
</ControlTemplate>

In my MainWindow code behind, I dynamically create a variable number of controls having this template

var template = this.FindResource("CriterionTemplate") as ControlTemplate;
GroupBox gb = new GroupBox()
{
    Template = template,
    Header = "MyCustomHeader",
};
gb.ApplyTemplate();

I create a bunch of those groupboxes and add them to some stackpanel. So far so good. Problem now is that the Header attribute of the groupbox is not set . Its just blank. The groupbox itsself with the template looks perfect, just the Header is empty. Once I remove the template, the Header is displayed correctly.

What do I do wrong?

Answer 1

In your template, you haven't specified how and where your Header will be displayed.

Once you decide to show Header in a Label, you need to

1. Set TargetType of Control Template to GroupBox . This will make sure that TemplateBinding of GroupBox properties work.

2. You have to do TemplateBinding like this

   <Label Content = "{TemplateBinding Header}">

Answer 2

Got the solution by myself.

There was a structural problem within the code itsself. I defined two GroupBoxes. One within the template, one outside in the code-behind.

To modify the Header of the outer GroupBox in the code-behind did nor reflect the UI, however modifying the inner one which is defined in the template DID.

Anyway I have to re-think my design here.