swift版的CircleView

效果图

源码

//
//  CircleView.swift
//  CircleView
//
//  Created by YouXianMing on 15/10/7.
//  Copyright © 2015年 YouXianMing. All rights reserved.
//

import UIKit

class CircleView: UIView {

    // MARK: - 变量

    var lineWidth  : CGFloat        = 1
    var lineColor  : UIColor        = UIColor.blackColor()
    var clockWise  : Bool           = false
    var startAngle : CGFloat        = 0
    var duration   : NSTimeInterval = 0.2

    private var circleLayer : CAShapeLayer!

    // MARK: - Public Method

    /**
    构建view,让参数生效
    */
    func buildView() {

        let size   = bounds.size
        let point  = CGPoint(x: size.height / 2, y: size.width / 2)
        let radius = size.width / 2 - lineWidth / 2

        var tmpStartAngle : CGFloat = 0
        var tmpEndAngle   : CGFloat = 0

        if (clockWise == true) {

            tmpStartAngle = -radian(Double(180 - startAngle));
            tmpEndAngle   = radian(Double(180 + self.startAngle));

        } else {

            tmpStartAngle = radian(Double(180 - self.startAngle));
            tmpEndAngle   = -radian(Double(180 + self.startAngle));
        }

        let circlePath = UIBezierPath(arcCenter: point, radius: radius, startAngle: tmpStartAngle, endAngle: tmpEndAngle, clockwise: clockWise)

        circleLayer.path        = circlePath.CGPath
        circleLayer.strokeColor = lineColor.CGColor
        circleLayer.fillColor   = UIColor.clearColor().CGColor
        circleLayer.lineWidth   = lineWidth
        circleLayer.strokeEnd   = 0
    }

    /**
    绘制圆形百分比

    - parameter percent:  百分比
    - parameter animated: 是否开启动画
    */
    func changeToPercent(var percent : CGFloat, animated : Bool) {

        if (percent <= 0) {

            percent = 0;

        } else if (percent >= 1) {

            percent = 1;
        }

        if (animated) {

            let basicAnimation : CABasicAnimation! = CABasicAnimation()
            basicAnimation.keyPath                 = "strokeEnd"
            basicAnimation.duration                = (duration <= 0 ? 0.2 : duration)
            basicAnimation.fromValue               = circleLayer.strokeEnd
            basicAnimation.toValue                 = percent
            circleLayer.strokeEnd                  = percent
            circleLayer.addAnimation(basicAnimation, forKey: nil)

        } else {

            CATransaction.setDisableActions(true)
            circleLayer.strokeEnd = percent
            CATransaction.setDisableActions(false)
        }
    }

    // MARK: - System Method

    override init(frame: CGRect) {

        super.init(frame: frame)
        createCircleLayer()
    }

    required init?(coder aDecoder: NSCoder) {

        fatalError("init(coder:) has not been implemented")
    }

    // MARK: - Private Method

    private func radian(degrees : Double) -> CGFloat {

        return CGFloat((M_PI * degrees) / 180)
    }

    private func createCircleLayer() {

        circleLayer       = CAShapeLayer()
        circleLayer.frame = self.bounds
        self.layer.addSublayer(circleLayer)
    }
}

//
//  ViewController.swift
//  CircleView
//
//  Created by YouXianMing on 15/10/7.
//  Copyright © 2015年 YouXianMing. All rights reserved.
//

import UIKit

class ViewController: UIViewController {

    var eventTimer : NSTimer!
    var circleView : CircleView!

    override func viewDidLoad() {
        super.viewDidLoad()

        eventTimer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "timerEvent", userInfo: nil, repeats: true)

        circleView            = CircleView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
        circleView.lineWidth  = 1
        circleView.lineColor  = UIColor.blackColor()
        circleView.duration   = 0.25
        circleView.clockWise  = true
        circleView.startAngle = 90
        circleView.center     = view.center
        circleView.buildView()

        view.addSubview(circleView)
    }

    func timerEvent() {

        circleView.changeToPercent(CGFloat(arc4random() % 101) / 100, animated: true)
    }
}

说明

参数查看并没有OC那么直白.