c# - UML diagram does not show details in visual studio 2012 -

I am using Visual Studio 2012 to create a UML diagram. Do this: Architecture -> New diagram -> UML class diagram

But the produced class graph does not have connections with each other, and there is nothing within each class, no features or operations, only A class name Actually there are many codes in the class, and they connect with each other, nobody knows why I found this simple graph?

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