Maybe I did not ask my question clear enough. What I want to achieve is when the user clicks on the "twitter button", he will be directed to an url such that a message has been pre-filled and the user just has to confirm whether he really wants to tweet.
In the thread of FAQ, Kyatric suggested some URL like
"https://twitter.com/intent/tweet?original_referer=XXX&text=My%20score&tw_p=tweetbutton&url=YYY"