ihealth_ios/Inhealth/IHGradientLayer.swift

//
//  IHGradientLayer.swift
//  Inhealth
//
//  Created by weclouds on 2020/4/29.
//  Copyright © 2020 weclouds. All rights reserved.
//

import UIKit

class IHGradientLayer: CALayer {
    var colors:[CGColor]?{
        didSet{
          setNeedsDisplay()
        }
    }
    override init() {
        super.init()
        
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    override func draw(in ctx: CGContext) {
        if let colors = self.colors{
            let endRadius = sqrt(pow(frame.width/2, 2) + pow(frame.height/2, 2))
            let center = CGPoint(x: bounds.size.width / 2, y: bounds.size.height / 2)
            
            let gradient = CGGradient(colorsSpace: nil, colors: colors as CFArray, locations: nil)
            ctx.drawRadialGradient(gradient!, startCenter: center, startRadius: 0.0, endCenter: center, endRadius: endRadius, options: CGGradientDrawingOptions.drawsBeforeStartLocation)
            
        }

    }
}