在项目开发中经常需要向用户展示一些提示信息，如“请输入...”、“网络...”等提示信息。为方便使用自定义了一个提示View.
该方法旨在供一些短小信息展示使用，文本最多显示两行。
代码如下：

enum AlignmentType:Int {
    case center = 0
    case bottom
}

final class TipsView: UIView {
    static let shared = TipsView()
    var textLab:UILabel?
    var alignment:AlignmentType = .center
    
    private init() {
        super.init(frame: UIScreen.main.bounds)
        self.setup()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        self.setup()
    }
    
    func setup() {
        self.alpha = 0.8
        self.backgroundColor = UIColor.colorWithHex("5B5B5B")
        self.layer.cornerRadius = 3.0
        self.textLab = UILabel.init()
        self.textLab?.textAlignment = .center
        self.textLab?.backgroundColor = UIColor.clear
        self.textLab?.textColor = UIColor.white
        self.textLab?.font = UIFont.systemFont(ofSize: 13)
        self.textLab?.numberOfLines = 2
        self.textLab?.sizeToFit()
        self.addSubview(self.textLab!)
    }
    
    func showTips(info:String) {
        self.textLab?.text = info
        self.layoutSubviews()
        UIApplication.shared.keyWindow?.addSubview(self)
        DispatchQueue.main.asyncAfter(deadline: DispatchTime.now()+2) {
            self.removeFromSuperview()
        }
    }
    
    func showTips(info:String,alignment:AlignmentType) {
        self.textLab?.text = info
        self.alignment = alignment
        self.layoutSubviews()
        UIApplication.shared.keyWindow?.addSubview(self)
        DispatchQueue.main.asyncAfter(deadline: DispatchTime.now()+2) {
            self.removeFromSuperview()
        }
    }
    
    override func layoutSubviews() {
        super.layoutSubviews()
        self.frame = CGRect(x: 0, y: 0, width: (self.textLab?.frame.size.width)!+20, height: (self.textLab?.frame.size.height)!)
        let paragraphStyle:NSMutableParagraphStyle = NSMutableParagraphStyle()
        paragraphStyle.lineBreakMode = .byWordWrapping
        let attributes:[NSAttributedStringKey:Any] = [NSAttributedStringKey(rawValue: NSAttributedStringKey.font.rawValue):(self.textLab?.font)!,NSAttributedStringKey.paragraphStyle:paragraphStyle.copy()]
        let lableSize:CGSize = (self.textLab?.text!.boundingRect(with: CGSize(width: 240, height: 100), options: [.usesLineFragmentOrigin,.usesFontLeading], attributes: attributes, context: nil).size)!
        
        self.frame = CGRect(x: self.frame.origin.x, y: self.frame.origin.y, width: lableSize.width+20, height: lableSize.height+20)
        if self.alignment == .bottom {
            self.center = CGPoint(x: DEVICE_WIDTH/2, y: DEVICE_HEIGHT-150)
        } else {
            self.center = CGPoint(x: DEVICE_WIDTH/2, y: DEVICE_HEIGHT/2)
        }
        self.textLab?.frame = self.bounds
    }
}

使用方式：

//默认居中显示
TipsView.shared.showTips(info: "收到通知")
//也可以在下方显示
TipsView.shared.showTips(info: "收到通知", alignment: .bottom)