Using WPF blur to focus attention...Why won't the whole screen gray out?

Question

I used this example to make the screen blur to focus attention. http://blog.wpfwonderland.com/2010/03/23/use-the-wpf-blur-effect-to-focus-attention/

I wanted the whole thing to grey out too, except only one user-control is graying out. I have a grid with 2 columns, left column is a tab control styled like outlook sidebar, and the right column is the main view. The main view grays out, the sidebar does not. Why? Is it because if the styles applied? The code is in the code behind of the main form that holds everything.

Answer 1

It sounds like you're just not applying the BlurEffect to the correct element. It needs to be on the outermost container the contents of which you want blurred. In this case, perhaps the Grid itself.

<Grid>
    <Grid.Effect>
        <BlurEffect Radius="0" />
    </Grid.Effect>

I always use animations with the BlurEffect, so the storyboards that increase and decrease the radius and the triggers that start the storyboards all reside in Resources and Triggers collections.

Answer 2

It is probably because other control styles on the page have the Background property defined, and that code only changes the Window background (so the Window background is behind the other control backgrounds).

In the past I've used a Rectangle object positioned between the Controls on the page and the Popup, and set the background of the rectangle to something transparent. There's probably better ways out there though.