swift UILabel中字体的自动换行以及行间距的设置

let lab=UILabel.init(frame: CGRectMake( 20, 0, SCREEN_WIDTH, 50))

let text=NSMutableAttributedString.init(string: "*租客关注“租嘛”公众号可查看下载电子合约\n*本页设置只影响新保存数据")

//设置缩进与行间距

let style=NSMutableParagraphStyle.init()

style.lineSpacing = 10;//行距

text.addAttribute(NSParagraphStyleAttributeName, value: style, range: NSMakeRange(0, text.length))

//自动截取换行

lab.lineBreakMode = NSLineBreakMode.ByWordWrapping

lab.numberOfLines = 0

//lab.text="快速发布到好好租\n58、赶集等平台"

lab.attributedText=text

lab.textAlignment=NSTextAlignment.Left

lab.font=UIFont.systemFontOfSize(12)

lab.textColor=UIColor.grayColor()