Getting a templated button's command to work

Question

I've used a control template to change the appearance of a button in a trivial way. It now looks different, but does not behave like a button. There are really two problems:

1. The button's command is never executed
2. After clicking on the button, it appears selected (i.e., the ellipse turns into an ugly blue rectangle)

Here's the general idea:

<Button Command="{x:Static commands:...}"
        CommandParameter="{Binding}">
    <Button.Template>
        <ControlTemplate TargetType="Button">
            <Ellipse Fill="{Binding ...}"
                     .../>
        </ControlTemplate>
    </Button.Template>
</Button>

Answer 1

1. There's no reason this should be happening. I put together a test using ApplicationCommands.Copy and the command fired just fine. Could be your CommandBinding isn't working properly.
2. I also didn't see this based on copying your sample XAML and just setting Fill="Green". You can try setting FocusVisualStyle="{x:Null}" on the Button.

Answer 2

The problem turned out to be that Fill was bound to a value that could be null. If the Fill brush is null rather than transparent, then there's nothing to click and the command doesn't get executed. As Drew mentioned, with a solid fill, the button works correctly.

Takeaway lesson: if you want to hide your shape but still have it respond to user interaction, use a transparent brush, not a null brush.