Excel UDF can't get current Appliction.

[simon zhao]

Hi guys:
I develop an Add-in in C#.There is a ribbon menu and several UDFs. The problem is I can't get current Applicaion in UDF. One UDF code is like:
public string GetActiveSheetN ame()
{
return Globals.ThisAdd In.Application. ActiveSheet.Nam e;
}

[simon zhao]

Example project

Nobody knows it?????