NSMutableAttributedString * attributedString1 = [[NSMutableAttributedString alloc] initWithString:testString];
NSMutableParagraphStyle * paragraphStyle1 = [[NSMutableParagraphStyle alloc] init];
[paragraphStyle1 setLineSpacing:15];//设置间距的主要代码
[attributedString1 addAttribute:NSParagraphStyleAttributeName value:paragraphStyle1 range:NSMakeRange(0, [testString length])];
[cLabel setAttributedText:attributedString1];
[cLabel sizeToFit];
