It's been a pleasure working with you.
跟你工作的这段日子我非常愉快。

It's been a pleasure..
It's been a pleasure to do/doing
...是我的庆幸/让我感到非常开心
It's been a pleasure to be here.
能够来到这里是我的荣幸。
It's been a pleasure to be invited to attend this meeting.
能够被邀请来参加这个会议是我的荣幸。
It's been a pleasure knowing you.
能够认识你是我的荣幸。

A:I have applied for a transfer.
我已经申请调职。
B:Really?Do you mean that you are leaving?
真的吗？你的意思是你要离职吗？
A:Yes,I think it's time to move on.I've already been here too long.
是的。是该有所改变了。我在这儿待了太久了。
B:Where do you want to go?
你想到哪儿去呢？
A:Well.I want to be transferred to the Shanghai office.
我想调任到上海办事处。
B:I will miss you.But anyway I wish you every success at your new post.
我会想你的。但不管怎么样。祝你在新的岗位上一切顺利。
A:Thanks.It's been a pleasure working with you.
谢谢。跟你工作的这段日子我非常愉快。