Swift - 绘制背景线条

 

效果

 

源码

////  BackgroundLineView.swift//  LineBackgroundView////  Created by YouXianMing on 16/8/14.//  Copyright © 2016年 YouXianMing. All rights reserved.//import UIKit// MARK: Public class : BackgroundLineViewclass BackgroundLineView: UIView {    // MARK: Properties.        /// Line width, default is 5.    var lineWidth : CGFloat {            get {
   return backgroundView.lineWidth}                set(newVal) {                    backgroundView.lineWidth = newVal            backgroundView.setNeedsDisplay()        }    }        /// Line gap, default is 3.    var lineGap : CGFloat {                get {
   return backgroundView.lineGap}                set(newVal) {                        backgroundView.lineGap = newVal            backgroundView.setNeedsDisplay()        }    }        /// Line color, default is grayColor.    var lineColor : UIColor {                get {
   return backgroundView.lineColor}                set(newVal) {                        backgroundView.lineColor = newVal            backgroundView.setNeedsDisplay()        }    }        /// Rotate value, default is 0.    var rotate : CGFloat {            get {
   return backgroundView.rotate}                set(newVal) {                    backgroundView.rotate = newVal            backgroundView.setNeedsDisplay()        }    }        convenience init(frame: CGRect, lineWidth : CGFloat, lineGap : CGFloat, lineColor : UIColor, rotate : CGFloat) {                self.init(frame : frame)        self.lineWidth = lineWidth        self.lineGap   = lineGap        self.lineColor = lineColor        self.rotate    = rotate    }        // MARK: Override system method.        override func layoutSubviews() {                super.layoutSubviews()        setupBackgroundView()    }        override init(frame: CGRect) {                super.init(frame: frame)                self.layer.masksToBounds = true        self.addSubview(backgroundView)    }        required init?(coder aDecoder: NSCoder) {                fatalError("init(coder:) has not been implemented")    }        // MARK: Private value & func.        private let backgroundView = LineBackground(length: 0)        private func setupBackgroundView() {            let drawLength        = sqrt(self.bounds.size.width * self.bounds.size.width + self.bounds.size.height * self.bounds.size.height)        backgroundView.frame  = CGRectMake(0, 0, drawLength, drawLength)        backgroundView.center = CGPointMake(self.bounds.size.width / 2.0, self.bounds.size.height / 2.0)        backgroundView.setNeedsDisplay()    }}// MARK: Private class : LineBackgroundprivate class LineBackground : UIView {    private var rotate    : CGFloat = 0    private var lineWidth : CGFloat = 5    private var lineGap   : CGFloat = 3    private var lineColor : UIColor = UIColor.grayColor()        override init(frame: CGRect) {                super.init(frame: frame)        self.backgroundColor = UIColor.clearColor()    }        required init?(coder aDecoder: NSCoder) {                fatalError("init(coder:) has not been implemented")    }        convenience init(length : CGFloat) {                self.init(frame : CGRectMake(0, 0, length, length))    }        override func drawRect(rect: CGRect) {                super.drawRect(rect)                if self.bounds.size.width <= 0 || self.bounds.size.height <= 0 {                        return        }                let context      = UIGraphicsGetCurrentContext()        let width        = self.bounds.size.width        let height       = self.bounds.size.width        let drawLength   = sqrt(width * width + height * height)        let outerX       = (drawLength - width)  / 2.0        let outerY       = (drawLength - height) / 2.0        let tmpLineWidth = lineWidth <= 0 ? 5 : lineWidth        let tmpLineGap   = lineGap   <= 0 ? 3 : lineGap                var red   : CGFloat = 0        var green : CGFloat = 0        var blue  : CGFloat = 0        var alpha : CGFloat = 0                CGContextTranslateCTM(context, 0.5 * drawLength, 0.5 * drawLength)        CGContextRotateCTM(context, rotate)        CGContextTranslateCTM(context, -0.5 * drawLength, -0.5 * drawLength)                lineColor.getRed(&red, green: &green, blue: &blue, alpha: &alpha)        CGContextSetRGBFillColor(context, red, green, blue, alpha)                var currentX = -outerX                while currentX < drawLength {                        CGContextAddRect(context, CGRectMake(currentX, -outerY, tmpLineWidth, drawLength))            currentX += tmpLineWidth + tmpLineGap        }                CGContextFillPath(context)    }}

 

使用

////  ViewController.swift//  LineBackgroundView////  Created by YouXianMing on 16/8/14.//  Copyright © 2016年 YouXianMing. All rights reserved.//import UIKitclass ViewController: UIViewController {    let tmpView = BackgroundLineView(frame: CGRectMake(0, 0, 300, 300), lineWidth: 4, lineGap: 4,                                     lineColor: UIColor.blackColor().colorWithAlphaComponent(0.045), rotate: CGFloat(M_PI_4))        override func viewDidLoad() {                super.viewDidLoad()        tmpView.center = self.view.center        self.view.addSubview(tmpView)    }}