Databinding to Command in Silverlight Templated Button control - silverlight

Question

I am trying to create a templated button control with databinding for the Visibility, tooltip, and Command. The Visibility binding works, as does the tooltip, but the Command does not. Another process is responsible for injecting the viewmodel and associating it with the View, and the other data bindings are working so I am pretty confident that is working properly.
In the resource dictionary:
<Converters:BoolToVisibilityConverter x:Key="boolVisibilityConverter" />
<Style TargetType="local:ImageButton">
<Setter Property="Visibility" Value="{Binding FallbackValue=Visible, Path=ToolIsAvailable, Converter={StaticResource boolVisibilityConverter} }"/>
<Setter Property="Command" Value="{Binding ButtonCommand}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="local:ImageButton">
<Grid>
<Image Source="{TemplateBinding Image}"
ToolTipService.ToolTip="{Binding ToolName}" />
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
the templated control
public class MyButton: ImageButton
{
public MyButton(MyCommandViewModel viewmodel)
{
this.DefaultStyleKey = typeof(ImageButton);
this.Image = new BitmapImage(new Uri("/MyProject;component/Themes/myimage.png", UriKind.Relative));
this.DataContext = viewmodel;
}
}
and in the view model
public MyCommandViewModel()
: base("My Tool", true)
{
}
public class CommandViewModel
{
public CommandViewModel(string toolName, bool isAvailable)
{
ToolIsAvailable = isAvailable;
ToolName = toolName;
_buttoncommand = new DelegateCommand(() =>
{
ExecuteCommand();
},
() => { return CanExecute; });
}
private bool _canExecute = true;
public bool CanExecute
{
get { return _canExecute; }
set
{
_canExecute = value;
OnPropertyChanged("CanExecute");
if (_command != null) _command.RaiseCanExecuteChanged();
}
}
private DelegateCommand _buttoncommand;
public ICommand ButtonCommand
{
get { return _buttoncommand; }
}
protected virtual void ExecuteCommand()
{
}
public bool ToolIsAvailable
{
get { return _toolIsReady; }
set { _toolIsReady = value; OnPropertyChanged("ToolIsAvailable"); }
}
public string ToolName
{
get { return _toolName; }
set { _toolName = value; OnPropertyChanged("ToolName"); }
}
}
Why are the other databindings functioning properly but not the Command data binding. I found this similar post
Overriding a templated Button's Command in WPF
Do I need to template a grid control instead and use RoutedCommands? I am not sure I understand why Silverlight treats the Command binding different than the others so I suspect I just have a bug in the code.

Answer 1

Does specifically looking for the datacontext work?
Command="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type UserControl}}, Path=DataContext.ButtonCommand}"

Answer 2

This was my solution. Using the same commandviewmodel as above and same MyCommandViewModel
<Style TargetType="local:ImageButton">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="local:ImageButton">
<Grid>
<Image Source="{TemplateBinding Image}" />
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
The databinding is now done in a user control
<UserControl x:Class="SilverlightApplication11.Test"
...
>
<UserControl.Resources>
<Converters:BoolToVisibilityConverter x:Key="boolVisibilityConverter" />
</UserControl.Resources>
<Grid>
<local:ImageButton Image="/SilverlightApplication11;component/Themes/hand.png" Command="{Binding ButtonCommand}" Visibility="{Binding FallbackValue=Visible, Path=ToolIsAvailable, Converter={StaticResource boolVisibilityConverter} }"/>
</Grid>
</UserControl>
and the code behind
public Test(TestCommandViewModel vm)
{
InitializeComponent();
this.Loaded += (o, e) => this.DataContext = vm;
}