I''ve been working with Google APIs recently and most of the ones that I've used require OAuth2 authentication so that the user can grant the application access to their data. Rather than copy-and-paste the OAUTH2 implementation to the different projects that I'm using I decided to make a class library that included the authentication code. From a usage standpoint I wanted to to do something similar to the the tasks and choosers where you create an object, call a method, and after the component does its magic you get back the item that the user chose.
The format for the URI to another assembly that you would use in Silverlight looked like the following
new Uri("{assemblyName};component/{pagePath.xaml}", UriKind.Relative);
Of course here {assemblyName} and {pagePath.xaml} are placeholders for your actual assembly namd and pathway to the page and not literal values here. It took me more time than I care to admit to figure out why this would not work on Windows Phone 7. The correct format to use on Windows Phone 7 is as follows:
new Uri("/{assemblyName};component/{pagePath.xaml}", UriKind.Relative);
See the difference? It's subtle, but the difference is the little forward slash at the begining of the string. Had I paid closer attention to the exception message that was returned I would have realized this.
The one thing I don't like about this method is when one navigates away from the page any program state that is saved in the page's code-behind is going to be lost. I also plan to provide an alternative method for showing the OAUTH in a user control. Either method has its advantages and disadvantages. I'm alsmost done with the code and will be posting it here later this week.
Tags: Windows Phone