swift - warnView 提醒小圆点

//
//  GA_WarnView.swift
//  GA_Kingfisher
//
//  Created by houjianan on 2017/1/6.
//  Copyright © 2017年 houjianan. All rights reserved.
//

import UIKit
private let kWarnViewKey = "warnView"
extension UIView {
    
    private var warnView: UIView? {
        set {
            objc_setAssociatedObject(self, kWarnViewKey, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
        }
        get {
            if let v = objc_getAssociatedObject(self, kWarnViewKey) as? UIView {
                return v
            }
            return nil
        }
    }
    
    func addWarnView(origin: CGPoint, size: CGFloat, color: UIColor) {
        warnView = UIView()
        warnView?.tag = 201
        warnView?.frame = CGRect(x: origin.x, y: origin.y, width: size, height: size)
        warnView?.backgroundColor = color
        warnView?.layer.masksToBounds = true
        warnView?.layer.cornerRadius = size / 2
        self.addSubview(warnView!)
        
//        self.perform(#selector(UIView.dismiss), with: self, afterDelay: 2)
    }
    
    func showWarnView(origin: CGPoint, size: CGFloat, color: UIColor) {
        addWarnView(origin: origin, size: size, color: color)
    }
    
    func dismiss() {
        if let warnView = warnView {
            warnView.removeFromSuperview()
        }
    }
    
    
}