c# - Error passing both a dynamic object and an Action to a function -


i trying pass dynamic object and action function. (below simple test) but, getting following compile time error:

cannot use lambda expression argument dynamically dispatched operation without first casting delegate or expression tree type.

one or other ok... not both... help?

    void test()     {         dynamic obj = new system.dynamic.expandoobject();         obj.a = 1;         obj.b = 2;         calc(obj, (result) =>         {             console.write("result: " + result);         });         }      void calc(dynamic obj, action<int> oncomplete)     {         oncomplete((int)obj.a + (int)obj.b);     }

sure - compiler says - cast lambda expression concrete type:

calc(obj, (action<int>)(result => console.write("result: " + result)));

the reason have lambda expression doesn't have type - compiler has know delegate (or expression tree) type you're trying convert to. can't if method you'll calling won't chosen until execution time, case when argument dynamic.


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