/*
计算字符宽度
*/
NSString *str=@"一";
CGSize size=CGSizeMake(270, MAXFLOAT);
UIFont * font= FontSizeChange(14);
NSDictionary *attrs=@{NSFontAttributeName:font};
CGSize s =[str boundingRectWithSize:size options:NSStringDrawingTruncatesLastVisibleLine |
NSStringDrawingUsesLineFragmentOrigin |
NSStringDrawingUsesFontLeading attributes:attrs context:nil].size;