SystemExpressions puzzled me , How to use SystemExpressions in python scripts?
Help files tells me that : LayerName(number) Returns name of the given layer number.
I think that ,LayerName is a function, it has a argument "number".
but when a write the script, I find that when i writer" System.LayerName(1)", error happend,
"'NoneType' object is not call able".
Who can tell me the right way to use "LayerName" ?