sizeWithFont:constrainedToSize:转boundingRectWithSize:options:

CGFloat width1=[(NSString *)ob1 sizeWithFont:[UIFont systemFontOfSize:16] constrainedToSize:CGSizeMake(1000, FONTHEIGHT)].width;

转

CGFloat width1=[(NSString *)ob1 boundingRectWithSize:CGSizeMake(1000, FONTHEIGHT) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{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