capture events from lookless control button - silverlight

Question

I have create a lookless control to be used in a Silverlight 4 project. This control contains a button and I would like to capture the click event. The Generic.xaml contains
<Style TargetType="TU:MyControl">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="TU:MyControl" >
<Border Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}" d:DesignWidth="550" d:DesignHeight="228">
<Grid Background="Silver">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="150*"/>
<ColumnDefinition Width="60"/>
<ColumnDefinition Width="150*"/>
</Grid.ColumnDefinitions>
<Border Grid.Column="0" Margin="2" BorderBrush="DarkGray" BorderThickness="3"></Border>
<Border Grid.Column="2" Margin="2" BorderBrush="DarkGray" BorderThickness="3"></Border>
<StackPanel Grid.Column="1">
<Button Name="PART_MyClick" Height="32" Width="32" Margin="0,8,0,0"></Button>
</StackPanel>
</Grid>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
After researching the problem I beleive that I have to add the following attribute to my control class
[TemplatePart(Name = "PART_MyClick", Type = typeof(Button))]
Then in my controls constructor I have added the following code
var myClick = GetTemplateChild("PART_MyClick") as Button;
if(myClick != null)
{
myClick.Click += (o, e) => DoThings();
}
when run though the myClick variable is always null so the event handler never gets attached. Could you please tell me where I am going wrong? Im a newbie so if this is the wrong approach completly then any advise on the correct approach would also be greatfully received

Answer 1

Override the OnApplyTemplate method and put your code there instead of the control's constructor:
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
var myClick = GetTemplateChild("PART_MyClick") as Button;
if(myClick != null)
{
myClick.Click += (o, e) => DoThings();
}
}
Because during the constructor call the visual tree for the control is not build up yet. From MSDN OnApplyTemplate:
Attach class-defined event handlers to parts of the template. For
example, you might want class logic to handle KeyDown events from a
TextBox template part so that UI states are updated, and other events
that are specific to your control are raised instead.