The MainPage.c<> class is not the view constructor. It's a helper class created by the compiler to implement anonymous delegates. Only one instance of this class will be created, and it will not be GCed until the AppDomain shuts down (it has a static field reference as a root). The size of the instance is only 12 bytes and since only one instance gets created, it's not a memory leak, just an implementation detail.
I hope this helps.
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