问题
Apparently Excel is hardcoded to only allow 255 characters in footers (and headers I think). Naturally I wanted to put more than that in the footer hence this post.
Header Workaround:
I found that putting stuff in the RDLC header and setting PrintsOnFirstPage and PrintsOnLastPage to true, when exported DOESN'T actually put the RDLC header items into the Excel Header it just uses a split region (with an empty Excel header) and you can put in as much as you like. Visually it's OK but obviously it won't print on every page, but presumably you could use the old trick of editing the resulting worksheet to repeat rows on pages.
Footer Workaround:
Sadly I've not found a similar workaround for the footer though as RDLC footers DO get put into the Excel footer and that as mentioned is limited to 255 characters.
This is a gotcha that I never imagined when designing my reports.
Anyone got any ideas on how to get around the footer character limit? (beyond "create a screenshot" that is.)
Note: this is a response to this question, and to get answer to my footer issue if possible.
来源：https://stackoverflow.com/questions/4944277/rdlc-to-excel-export-header-and-footer-character-limit