/******label随字体改变宽度******/

+ (CGSize)sizeWithString:(NSString *)string font:(UIFont *)font{

CGRect rect = [string boundingRectWithSize:CGSizeMake(CGFLOAT_MAX, CGFLOAT_MAX)//限制最大高度

options:NSStringDrawingTruncatesLastVisibleLine | NSStringDrawingUsesFontLeading |NSStringDrawingUsesLineFragmentOrigin//采用换行模式

attributes:@{NSFontAttributeName: font}//传入的字体字典

context:nil];

return rect.size;

}