Windows Phone 7: Tombstoning tips

After a hard week of optimzing the memory consuption and tombstoning in my current Windows Phone 7 project, here are some of the major points, especially if you working with a multmedia application for Windows Phone 7:

• Do our own serialization/deseralization (using DataContractSerializer) (because of the 2 MB limitation for transient data)
• Use virtualization in all lists with a big amount of data (see Shawn Oster | Improving ListBox Performance in Silverlight for Windows Phone 7: Data Virtualization)
• Work with <WeakReference> for bitmap objects
• Cleanup references after NavigateFrom
• If you are using Listboxes with a great amount of data:
• In NavigateFrom: Set the Listbox items source to null
• After this the tombstoning is much quicker and memory consumption is lower
• otherwise the applications crashes here during tombstoning again, because the framework reachs the limit (2MB) with all the bitmaps on the page