Silverlight supports the ScriptableType and ScriptableMember attributes that make classes and members accessible from test scripts.
After you apply these attributes to classes or members in the source code of your
Silverlight application, the class or member will be accessible to the external script and you can call them from your automated tests.
This feature lets you work with classes and members outside of the application's code and makes it easier to call them from your TestComplete tests.
We've published an article explaining how to use this feature to create unit tests for your Silverlight applications and automate them with TestComplete. We hope you enjoy!
Automated Unit Testing of Silverlight Application