About this problem,I get an answer by learned programmer as that the macor“GENERATED_BODY()” can not be included in another macro.
So,it is the reason that TRange code like this.And there is a remian problem,is that without macro “USTRUCT()” and “GENERATED_BODY()”,the new create struct can not be notice by PropertySystem.
I can not edit it in Blueprint.
I scan sourceCode of engine by keyword “TRange<>” or “FDoubleRange”,can not find their reflection code,or their propertydetail that definite interaction in blueprint.Where it is codeed?