Swift - 绘制背景线条

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 : BackgroundLineView
 
class 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: )
 
    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(, , drawLength, drawLength)
        backgroundView.center = CGPointMake(self.bounds.size.width / 2.0, self.bounds.size.height / 2.0)
        backgroundView.setNeedsDisplay()
    }
}
 
// MARK: Private class : LineBackground
 
private class LineBackground : UIView {
 
    private var rotate    : CGFloat =
    private var lineWidth : CGFloat =
    private var lineGap   : CGFloat =
    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(, , length, length))
    }
 
    override func drawRect(rect: CGRect) {
 
        super.drawRect(rect)
 
        if self.bounds.size.width <=  || self.bounds.size.height <=  {
 
            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 <=  ?  : lineWidth
        let tmpLineGap   = lineGap   <=  ?  : lineGap
 
        var red   : CGFloat =
        var green : CGFloat =
        var blue  : CGFloat =
        var alpha : CGFloat = 
 
        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 UIKit
 
class ViewController: UIViewController {
 
    let tmpView = BackgroundLineView(frame: CGRectMake(, , , ), lineWidth: , lineGap: ,
                                     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)
    }
}