WPF: Wrapping a label/TextBlock in a rectangular border

I'd like to draw a big number on a Canvas, wrapped in a rectangle, but I don't know how to do that. My idea is to create a style and then to apply it to some Label instance which changes its size:

<Style x:Key="CountdownLabel" TargetType="Label">
<Setter Property="FontFamily" Value="Arial"></Setter>
<Setter Property="Foreground" Value="Navy"></Setter>
<Setter Property="FontWeight" Value="Bold"></Setter>
<Setter Property="FontSize" Value="40"></Setter>
<Setter Property="FontStretch" Value="UltraExpanded"></Setter>
<Set开发者_开发百科ter Property="Control.Template">
    <Setter.Value>
        <ControlTemplate>
            <Border>
                <Rectangle Margin="0,0,0,0" Stroke="#60000000" StrokeThickness="1" StrokeDashArray="1 2" />
            </Border>
        </ControlTemplate>
    </Setter.Value>
</Setter>

I set label.Content=number.ToString() in code-behind but the number is not showed. Also, I wouldn't know how to resize the label for filling the Canvas parent.

Regards.

---

There are two things you need to correct in your template:

1. You don't include a ContentPresenter, so there's nothing to tell the layout system "oh, by the way, here's where you should insert what's in the Label's Content property".
2. You need to specify TargetType on your ControlTemplate. (Just one of those things you learn to try when templates aren't working.)

Here's an adjusted version that works. I changed your Border to a Grid so it could accommodate two child controls (the Rectangle for the dashed border, and a ContentPresenter to show the Content). I stole the ContentPresenter declaration from an example on MSDN; it may not be complete, but it should get you started.

<Style x:Key="CountdownLabel" TargetType="Label">
  <Setter Property="FontFamily" Value="Arial"/>
  <Setter Property="Foreground" Value="Navy"/>
  <Setter Property="FontWeight" Value="Bold"/>
  <Setter Property="FontSize" Value="40"/>
  <Setter Property="FontStretch" Value="UltraExpanded"/>
  <Setter Property="Control.Template">
    <Setter.Value>
      <ControlTemplate TargetType="Label">
        <Grid>
          <Rectangle Margin="0,0,0,0" Stroke="#60000000" StrokeThickness="1"
                     StrokeDashArray="1 2" MinWidth="10" MinHeight="10"/>
          <ContentPresenter
            HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
            VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
            RecognizesAccessKey="True" />
        </Grid>
      </ControlTemplate>
    </Setter.Value>
  </Setter>
</Style>