Hi lrosenth
Thank you so much for your reply.
I find answer in google. And find a similar question:
iphone - How to output a Euro symbol in a PDF - Stack Overflow
Thats because MacRomanEncoding doesn't contain euro symbol by default, see this quote from "PDF reference 1.7" (Section D.1 Latin Character Set and Encodings)
so I think "My original" code is right.But I still did not know, Why the warning message will pop up. Can you give me your email, I will send your the "problem" pdf file and help me to find the reason.
Thanks again.