sizeWithFont:constrainedToSize:转boundingRectWithSize:options:

CGFloat width1=[(NSString *)ob1 sizeWithFont:[UIFontsystemFontOfSize:16] constrainedToSize:CGSizeMake(1000,FONTHEIGHT)].width;
转
CGFloat width1=[(NSString *)ob1boundingRectWithSize:CGSizeMake(1000, FONTHEIGHT)options:NSStringDrawingUsesLineF

ragmentOriginattributes:@{NSFontAttributeName:[UIFont systemFontOfSize:16]}context:nil].size.width;

boundingRectWithSize: CGSize 对应constrainedToSize:CGSize
attributes:@{NSFontAttributeName: [ UIFont ] }对应 sizeWithFont[UIFont ]
options: NSStringDrawingUsesLineFragmentOrigin 默认照填
context: nil 默认照填