It's my pleasure和With pleasure有什么区别？怎么用

It's my pleasure和With pleasure有什么区别？怎么用

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.

(1)thank you for helping me.
it's my pleasure

(2)would you please open the widow?
with pleasure.

可见it's my pleasure是回答别人的感谢的，可译为“那是我应该做的”，而whth pleasure是回答别人的请求的，可译为“好的，乐意效劳”。

第一句是谢谢的意思。