如何在iOS中设置drawRect时的不同笔划颜色

import UIKit

class CustomView: UIView {
    override func drawRect(rect: CGRect) {
        // 创建路径
        let path = UIBezierPath(rect: rect)
        
        // 设置不同笔划的颜色
        let color1 = UIColor.redColor()
        let color2 = UIColor.greenColor()
        let color3 = UIColor.blueColor()
        
        // 设置路径的属性
        path.lineWidth = 2.0
        
        // 绘制路径
        color1.setStroke()
        path.stroke()
        
        color2.setStroke()
        path.stroke()
        
        color3.setStroke()
        path.stroke()
    }
}