ImageBrush renders white when not debugging application - xaml

Question

I got some strange black magic going on with my app.
I have defined an ImageBrush in a style dictionary:
<classes:MultiResImageChooser x:Key="MultiResImageChooser"/>
<ImageBrush x:Name="SplashScreenImageBrush"
ImageSource="{Binding SplashScreenResolutionImage, Source={StaticResource MultiResImageChooser}}"
Stretch="Fill" />`
The MultiResImageChooser class has a one simple property:
public class MultiResImageChooser
{
public BitmapImage SplashScreenResolutionImage
{
get
{
switch (ResolutionHelper.CurrentResolution)
{
case Resolutions.HD720p:
return new BitmapImage(new Uri("/Images/SplashScreenImage.Screen-720p.jpg", UriKind.Relative));
case Resolutions.WXGA:
return new BitmapImage(new Uri("/Images/SplashScreenImage.Screen-WXGA.jpg", UriKind.Relative));
case Resolutions.WVGA:
return new BitmapImage(new Uri("/Images/SplashScreenImage.Screen-WVGA.jpg", UriKind.Relative));
default:
throw new InvalidOperationException("Unknown resolution type");
}
}
}
}
SplashScreenImageBrush is binded to the background property of a Border element:
<Border x:Name="SplashScreen"
Background="{StaticResource SplashScreenImageBrush}"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch" />
So, the problem is that when I debug the application on an WP8 emulator or WP8 device everything works fine.
When launching the app without debugging, the Border background property is rendered White.
The image files are included in the project and have the Build Action set to Content.
Also, if I set the ImageSource directly to an image path, everything works.
So, the problem seems to be the MultiResImageChooser, but I do not know what could be wrong with it.
Any kind of help or hints will be greatly appreciated.
BTW, this issue does not get reproduced on w WP7.1 device and emulator.

Answer 1

My bet: ResolutionHelper.CurrentResolution doesn't work properly for some reason (timing issue?), so the "default" branch of your switch is executed. Your binding therefore fails, the brush doesn't get initialized, and you get a white color instead. From there, I'd start by confirming the execution of the "default" branch, for instance by putting a specific image instead of throwing an exception. Then, if my theory is right, look into the ResolutionHelper to understand what's going on.