When your WP7 app won't start

I've recently had a few problems where some of my WP7 apps simply won't start.

This isn't a problem with code... App.xaml.cs never gets loaded - so there's no way I can debug it.

If this happens to you, then here are my suggestions:

1. Check that the App.xaml file is marked as ApplicationDefinition and not as Page

2. Check that the App.xaml.cs class is set as the startup object in the project properties

3. Check that the App.xaml does not contain any corrupt entries in Application.Resources (this feels wrong... but I've seen issues with it)

4. Check that the project properties - for namespace, assembly, etc - are all their "normal" values

Hope this saves someone out there some swearing :)

A quick analysis of file size versus JPEG quality

For a sample genuine photo - http://upload.wikimedia.org/wikipedia/commons/0/0b/ReceiptSwiss.jpg - with all its analog goodness, I just used Paint.Net to resize the photo to 972x1296 and to produce:

Quality(%)   FileSize PNG          2MB 100%         749KB 95%          239KB 90%          153KB 75%          84KB 50%          57KB 25%          41KB

Pictures and more at http://slodge.com/photocompression/