beginners problem with WPF

I just started with WPF and the firs problem I found before I wrote a line of the code.
I attached here the picture and I want to know how to remove this black box from the window.
I'm sure it is very easy but I don't know how ).
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mastiSoftAuthor Commented:
this is the screenshot
AndyAinscowFreelance programmer / ConsultantCommented:
You haven't posted a screenshot yet
NorieAnalyst Assistant Commented:
No attachment.:)
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mastiSoftAuthor Commented:
now the attachment added )
AndyAinscowFreelance programmer / ConsultantCommented:
Not !!
That window is only there for debugging.  If you run the production exe it won't be there, but if you click on items in it, will help you debug the visual tree and pinpoint different elements.
Strictly there to ease debugging and is just part of being run through VS.
FYI, if you really need to turn it off, I believe it's from Tools -> Options -> Debugging -> General -> "Enable UI Debugging Tools for XAML"
But again, can be super useful.

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AndyAinscowFreelance programmer / ConsultantCommented:
I've just met something new - you can edit the question despite comments having been entered.
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