自適應長度的UILabel

CGSize size = CGSizeMake(320,12); //設置最大值
nickNameLabel.numberOfLines = 1;  //設置行數
CGSize labelsize = [nickNameLabel.text sizeWithFont:nickNameLabel.font constrainedToSize:size lineBreakMode:NSLineBreakByWordWrapping];  //字符串在指定字體和約束下的size
[nickNameLabel setFrame:CGRectMake(nickNameLabel.frame.origin.x, nickNameLabel.frame.origin.y, labelsize.width, labelsize.height)];