abel.numberOfLines=0;
[self.view addSubview:label];
//设置行间距
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc]init];
paragraphStyle.lineSpacing = 50;
NSDictionary *attributes = @{ NSFontAttributeName:[UIFont systemFontOfSize:14], NSParagraphStyleAttributeName:paragraphStyle};
label.attributedText = [[NSAttributedString alloc]initWithString:label.text attributes:attributes];
