I have an issue with the XAML designer for MainPage.xaml, it does not show the black screen of the phone. Instead it shows the invisible background. This means that just the body of the phone is visible but the screen matches the phone background.
When a Button is added to the Grid, just the outline for changing the size of the Button in seen and not the contents of the Button.
This answer works for any project in Visual Studio, not just windows phone.
Set the background of the Page
or Grid
or specific control to the color desired.
Background="Green"
If this is only a design time issue...one can change the colors of the background of the designer to an alternate color.
Go to Options -> Fonts and Colors
and select XAML Designer
in the Show settings for drop down. The in the Artboard Background
change both colors to a color which works for you. Mixing the colors will create a checkerboard view, so its usually best to use, black or white.