iOS UILabel设置中划线不能包含中文

NSMutableAttributedString *attStr = [[NSMutableAttributedString alloc] initWithString:@"15.0元"];
[attStr addAttributes:@{NSStrikethroughStyleAttributeName: [NSNumber numberWithInteger:NSUnderlineStyleSingle],
                                NSBaselineOffsetAttributeName : @(NSUnderlineStyleSingle)} range:NSMakeRange(0,attStr.length)];

[_origPriceLabel setAttributedText:attStr];