UILabel實用設定行間距程式碼，直接上程式碼

swift：

 fileprivate  func createUI(){

        let subLabel = UILabel()

        subLabel.font = UIFont(name: "EuphemiaUCAS", size: 19.0)
        subLabel.numberOfLines = 0
        subLabel.backgroundColor = UIColor.orange

        let subStr = "for-in 語句在迴圈開始前會呼叫集合表示式的 generate  方法來獲取一個實現了 GeneratorType 協議的型別的值。接下來迴圈開始，反覆呼叫該值的 next() 方法。如果其返回值不是 None，它將會被賦給“項”，然後執行迴圈體語句，執行完畢後回到迴圈開始處，繼續重複這一過程；否則，既不會賦值也不會執行迴圈體語句，for-in 語句至此執行完畢。"
 

        subLabel.attributedText = self .getAttributeStringWithString(subStr, lineSpace: 8.00)
        subLabel.centerX = self.view.centerX
        let fontSize = CGSize(width: kScreenW, height: subLabel.font.lineHeight)

        let rect:CGSize = subStr.boundingRect(with: fontSize, options: NSStringDrawingOptions.usesLineFragmentOrigin
 
, attributes: [NSFontAttributeName: subLabel.font], context: nil).size;

        subLabel.frame = CGRect(x: 15, y: 100, width: kScreenW, height: 200)
        subLabel.size = CGSize(width: rect.width-15, height: rect.height)
        subLabel.sizeToFit()

        self.view .addSubview(subLabel)

    }

    fileprivate func getAttributeStringWithString(_ string
 
: String,lineSpace:CGFloat
        ) -> NSAttributedString{
        let attributedString = NSMutableAttributedString(string: string)
        let paragraphStye = NSMutableParagraphStyle()

        //調整行間距
        paragraphStye.lineSpacing = lineSpace
        let rang = NSMakeRange(0, CFStringGetLength(string as CFString!))
        attributedString .addAttribute(NSParagraphStyleAttributeName, value: paragraphStye, range: rang)
        return attributedString

    }

oc：

        UILabel * subLabel = [[UILabel alloc]initWithFrame:CGRectMake(0, MainLabel.bottom+15*__kRatio, __kScreenWidth, 40)];
        subLabel.text = @"for-in 語句在迴圈開始前會呼叫集合表示式的 generate  方法來獲取一個實現了 GeneratorType 協議的型別的值。接下來迴圈開始，反覆呼叫該值的 next() 方法。如果其返回值不是 None，它將會被賦給“項”，然後執行迴圈體語句，執行完畢後回到迴圈開始處，繼續重複這一過程；否則，既不會賦值也不會執行迴圈體語句，for-in 語句至此執行完畢。";
        // 調整行間距
        subLabel.attributedText = [self getAttributedStringWithString:subLabel.text  lineSpace:8];

        subLabel.textColor = kColorA6A6A6;
        subLabel.font = _kFontMain;
        subLabel.numberOfLines =0;
        subLabel.textAlignment = NSTextAlignmentCenter;
        subLabel.size = [subLabel.text boundingRectWithSize:CGSizeMake(CGFLOAT_MAX, subLabel.font.lineHeight)
                                                      options:NSStringDrawingUsesLineFragmentOrigin
                                                   attributes:@{NSFontAttributeName : subLabel.font}
                                                      context:nil].size;
        subLabel.centerX = MainLabel.centerX;



        [subLabel sizeToFit];

        [_topView addSubview:subLabel];

// 調整行間距
-(NSAttributedString *)getAttributedStringWithString:(NSString *)string lineSpace:(CGFloat)lineSpace {
    NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:string];
    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    paragraphStyle.lineSpacing = lineSpace; // 調整行間距
    NSRange range = NSMakeRange(0, [string length]);
    [attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:range];
    return attributedString;
}