NSMutableAttributedString *arrString  =[[NSMutableAttributedString alloc]initWithString:@"asdassadklsjsdjaskljdklsajdlsajldjsla;jdl;sajdjlas;dsak"];
    NSMutableParagraphStyle *para = [[NSMutableParagraphStyle alloc]init];
    //行距
    [para setLineSpacing:12];
    //第一个属性 - 段落格式
    [arrString addAttribute:NSParagraphStyleAttributeName value:para range:NSMakeRange(0, [arrString length])];
    [self.label setAttributedText:arrString];
    [self.label sizeToFit];
    [self.view addSubview:self.label];