It's my pleasure与With pleasure的区别是什么？

It's my pleasure
或者it's省略 直接说 my pleasure
表示 ：不用谢。用于回答别人感谢
----thank you for your help.
----(It's )my pleasure.

with pleasure
表示：很荣幸,很乐意。用于回答别人请求。
----i know little about tennis .would you please teach me ?
----with pleasure.

It's my pleasure: 这是我的荣幸。
with pleasure ad. 愉快地(高兴地,十分愿意)

It's my pleasure.是我很荣幸的意思.
with pleasure是介词短语，意思是愉快地。