Neuro-Lab-how-to-specify-input-features-such-as-Close-MA-MA

QUOTE:
I think wl6 can use c# to do neural lab.

It's called Neuro-Lab, not neural lab. The NNP indicator is what you knew as NNIndicator in WL6 and it can be used in C# code.

QUOTE:
how to specify input features such as close -ma/ma (distance of close and ma)

Using one of the Transformer indicators such as MathIndOpInd.