自适应大小
CGSize size = [@"回复信息"sizeWithFont:[UIFont systemFontOfSize:14] constrainedToSize:CGSizeMake(tableView.frame.size.width - 10, MAXFLOAT) lineBreakMode:NSLineBreakByWordWrapping];
CGSize size = [@"回复信息"sizeWithFont:[UIFont systemFontOfSize:14] constrainedToSize:CGSizeMake(tableView.frame.size.width - 10, MAXFLOAT) lineBreakMode:NSLineBreakByWordWrapping];