Transparency for WPF UI elements

Is it possible in WPF to make a certai开发者_开发问答n element - say, a Canvas containing a button - semi-transparent? All I could find so far is how to make a whole window transparent or making the background of WPF shapes transparent; but that's not what I need.

Please provide the answers either in XAML or C# - I don't speak Visual Basic.

Something along the lines of this perhaps? Opacity is probably what you are looking for

<Button Width="200" Height="30" Opacity="0.5">
    Click Me!
</Button>