Repost of Determine Light or Dark Theme with WP7 RTM

This is not my content but a repost from http://mobileworld.appamundi.com/blogs/peterfoot/archive/2010/09/17/determine-light-or-dark-theme-with-wp7-rtm.aspx , I just wanted to ensure I didn’t lose it

In the previous Beta release you had to compare the RGB values of the background brush to determine if the theme was Light (White background) or Dark (Black background). Now there is an additional resource you can query:-

Visibility v = (Visibility)Resources["PhoneLightThemeVisibility"];
 
if (v == System.Windows.Visibility.Visible)
{
    ImageBrush ib = new ImageBrush();
    Uri u = new Uri("PanoramaBack2.png", UriKind.Relative);
    ib.ImageSource = new System.Windows.Media.Imaging.BitmapImage(u);
    PanoramaControl.Background = ib;
}

Any time you use a background image you can check the PhoneLightThemeVisibility resource and switch between different versions of the image to provide the best experience with either Black or White text.