I'm developing a Metro-style app (for Windows 8) using C# and XAML. I have set up my viewmodels to be used as design-time datacontexts, like so:
xmlns:vm="using:hub.ViewModels"
d:DataContext="{d:DesignInstance IsDesignTimeCreatable=True, Type=vm:ViewModels
My app appears to work perfectly when run, but in the design views of both VS 2012 and Blend, I occasionally get this (unhelpful) error message:
An Exception was thrown. TargetException: Error in the application.
Stacktrace
at System.ComponentModel.PropertyChangedEventHandler.Invoke(Object sender, PropertyChangedEventArgs e)
InnerException: None
This only happens in the design view - meaning I can't set breakpoints around all my INotifyPropertyChanged() events.
What is the best approach to debugging design-time errors?