获取带有emoji的字符串宽度和高度

// 得到带有emoji string长度和宽度

+ (CGSize) calculateEnojiStringSizeWithString:(NSString *) content font:(UIFont *) font constraintStringWidth:(CGFloat)stirngWidth

{

    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStylealloc]init];

    paragraphStyle.lineBreakMode =NSLineBreakByWordWrapping;

    NSDictionary *attributes =@{NSFontAttributeName:font,NSParagraphStyleAttributeName:paragraphStyle.copy};

    [paragraphStyle release];

    CGSize contentSize = [contentboundingRectWithSize:CGSizeMake(stirngWidth,MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin

                                                         attributes:attributes

                                                            context:nil].size;

    return contentSize;

}