What does prefix to MoveNext mean in the stackstace?

Question

The .NET application crashes with the stack trace:

Call Stack:

Layouts!Layouts.Ribbon.SizeAndPositionControlViewModel+OnLayoutSelectionChanged>d__5.MoveNext() 
mscorlib_ni!System.Runtime.CompilerServices.AsyncMethodBuilderCore.<ThrowAsync>b__0(System.Object)
WindowsBase_ni!System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32) 

The rest of the callstack is Windows code and does not matter.

Here's what the first call implies: In the async method OnLayoutSelectionChanged() in the instance of SizeAndPositionControlViewModel it failed in method MoveNext(). MoveNext() happens to be Microsoft code in a LINQ method method Any.

What does d__5 signify ?

Answer 1

The d__5 portion is a prefix that is generated by the C# compiler to keep the construct unique from other generated members / types. In this case the d prefix means that it is an iterator or async method generated class (d is used for both). The number is just incremented for every name that is generated