1.

    UILabel *lbl_oldPrice = [[UILabel alloc]initWithFrame:CGRectMake(100, 100, 200, 30)];
    lbl_oldPrice.font = [UIFont systemFontOfSize:14];
    lbl_oldPrice.backgroundColor = [UIColor greenColor];
    NSString *textStr = @"￥199";
  
    //中劃線
    NSDictionary *attribtDic1 = @{NSStrikethroughStyleAttributeName: [NSNumber numberWithInteger:NSUnderlineStyleSingle]};
    NSMutableAttributedString *attribtStr1 = [[NSMutableAttributedString alloc]initWithString:textStr attributes:attribtDic1];
    lbl_oldPrice.attributedText = attribtStr1;
    
    // 下劃線
    NSDictionary *attribtDic2 = @{NSUnderlineStyleAttributeName: [NSNumber numberWithInteger:NSUnderlineStyleSingle]};
    NSMutableAttributedString *attribtStr2 = [[NSMutableAttributedString alloc]initWithString:textStr attributes:attribtDic2];
    lbl_oldPrice.attributedText = attribtStr2;
    lbl_oldPrice.attributedText = attribtStr1;
    
    lbl_oldPrice.textColor = [UIColor grayColor];
    lbl_oldPrice.textAlignment = NSTextAlignmentLeft;
    [self.view addSubview:lbl_oldPrice];

2.

iOS10.3更新后陨享，商城APP這樣的UI：原價(jià) “￥500 ” 類似Label設(shè)置的中劃線突然失效了宫峦。
這可能是蘋果系統(tǒng)的一個(gè)bug。
根本原因：UILabel上的文字只要包含有“中文”囊蓝，富文本字符串的中劃線就會失效劫扒，我們可通過以下兩種方式解決。

第一種方式：人民幣符號“￥”和“￥”荡陷，使用前面一個(gè)即可雨效。

NSString *market = [NSString stringWithFormat:@"￥%@",@"500"];
NSMutableAttributedString *attributeMarket = [[NSMutableAttributedString alloc] initWithString:market];
[attributeMarket setAttributes:@{NSStrikethroughStyleAttributeName: [NSNumber numberWithInteger:NSUnderlineStyleSingle]} range:NSMakeRange(0,market.length)];

_marketLabel.attributedText = attributeMarket;

第二種方式：讓富文本支持“中文”

增加一個(gè)富文本屬性： NSBaselineOffsetAttributeName : @(NSUnderlineStyleSingle)

NSString *market = [NSString stringWithFormat:@"￥%@",@"500"];
NSMutableAttributedString *attributeMarket = [[NSMutableAttributedString alloc] initWithString:market];
[attributeMarket setAttributes:@{NSStrikethroughStyleAttributeName: [NSNumber numberWithInteger:NSUnderlineStyleSingle], NSBaselineOffsetAttributeName : @(NSUnderlineStyleSingle)} range:NSMakeRange(0,market.length)];

_marketLabel.attributedText = attributeMarket;