快速生成qrcode

Question

我试图生成一个qrcode，但是它有错误。

线程1:致命错误:在展开可选值时意外找到零

let myString = "ggigiuui"

let data = myString.data(using: .ascii, allowLossyConversion: false)
let filter = CIFilter(name: "CIQRCodeGenerator")
filter?.setValue(data, forKey: "inputMessage")

let img = UIImage(ciImage: (filter?.outputImage)!)

qponImage.image = img

​

​

Answer 1

我使用了以下代码，它正在工作，perfectly.Where self.imgQRCode是要在其上显示QR的图像视图。

func generateQRCode(from string: String) -> UIImage?
    {
        let data = string.data(using: String.Encoding.ascii)

        if let filter = CIFilter(name: "CIQRCodeGenerator")
        {
            filter.setValue(data, forKey: "inputMessage")

            guard let qrImage = filter.outputImage else {return nil}
            let scaleX = self.imgQRCode.frame.size.width / qrImage.extent.size.width
            let scaleY = self.imgQRCode.frame.size.height / qrImage.extent.size.height
            let transform = CGAffineTransform(scaleX: scaleX, y: scaleY)

            if let output = filter.outputImage?.transformed(by: transform)
            {
                return UIImage(ciImage: output)
            }
        }
        return nil
    }

Answer 2

请试试这个，

func generateQRCode(from string: String) -> UIImage? {
    let data = string.data(using: String.Encoding.ascii)

    if let filter = CIFilter(name: "CIQRCodeGenerator") {
        filter.setValue(data, forKey: "inputMessage")
        let transform = CGAffineTransform(scaleX: 3, y: 3)

        if let output = filter.outputImage?.transformed(by: transform) {
            return UIImage(ciImage: output)
        }
    }

    return nil
}

Answer 3

这是如何生成一个QRCode并在UIImageView中显示

首先，创建新的Cocoa类 .swift文件并导入这两个框架：

import UIKit
import CoreImage

第二步，只需将扩展 of 、URL、和CIImage添加到相同的.swift文件中即可。

扩展:

extension URL {

    /// Creates a QR code for the current URL in the given color.
    func qrImage(using color: UIColor, logo: UIImage? = nil) -> CIImage? {
        let tintedQRImage = qrImage?.tinted(using: color)
        guard let logo = logo?.cgImage else {
            return tintedQRImage
        }
        return tintedQRImage?.combined(with: CIImage(cgImage: logo))
    }
    
    /// Returns a black and white QR code for this URL.
    var qrImage: CIImage? {
        guard let qrFilter = CIFilter(name: "CIQRCodeGenerator") else { return nil }
        let qrData = absoluteString.data(using: String.Encoding.ascii)
        qrFilter.setValue(qrData, forKey: "inputMessage")
        let qrTransform = CGAffineTransform(scaleX: 12, y: 12)
        return qrFilter.outputImage?.transformed(by: qrTransform)
    }
}

extension CIImage {
    
    /// Inverts the colors and creates a transparent image by converting the mask to alpha.
    /// Input image should be black and white.
    var transparent: CIImage? {
        return inverted?.blackTransparent
    }
    
    /// Inverts the colors.
    var inverted: CIImage? {
        guard let invertedColorFilter = CIFilter(name: "CIColorInvert") else { return nil }
        invertedColorFilter.setValue(self, forKey: "inputImage")
        return invertedColorFilter.outputImage
    }
    
    /// Converts all black to transparent.
    var blackTransparent: CIImage? {
        guard let blackTransparentFilter = CIFilter(name: "CIMaskToAlpha") else { return nil }
        blackTransparentFilter.setValue(self, forKey: "inputImage")
        return blackTransparentFilter.outputImage
    }
    
    /// Applies the given color as a tint color.
    func tinted(using color: UIColor) -> CIImage?
    {
        guard
            let transparentQRImage = transparent,
            let filter = CIFilter(name: "CIMultiplyCompositing"),
            let colorFilter = CIFilter(name: "CIConstantColorGenerator") else { return nil }
        
        let ciColor = CIColor(color: color)
        colorFilter.setValue(ciColor, forKey: kCIInputColorKey)
        let colorImage = colorFilter.outputImage
        filter.setValue(colorImage, forKey: kCIInputImageKey)
        filter.setValue(transparentQRImage, forKey: kCIInputBackgroundImageKey)
        return filter.outputImage!
    }
    
    /// Combines the current image with the given image centered.
    func combined(with image: CIImage) -> CIImage? {
        guard let combinedFilter = CIFilter(name: "CISourceOverCompositing") else { return nil }
        let centerTransform = CGAffineTransform(translationX: extent.midX - (image.extent.size.width / 2), y: extent.midY - (image.extent.size.height / 2))
        combinedFilter.setValue(image.transformed(by: centerTransform), forKey: "inputImage")
        combinedFilter.setValue(self, forKey: "inputBackgroundImage")
        return combinedFilter.outputImage!
    }
}

第三步，您必须显示要显示生成的QRCode的图像视图的输出。

您的ViewController.swift文件如下所示。

  // desired color of QRCode
    let OrangeColor = UIColor(red:0.93, green:0.31, blue:0.23, alpha:1.00)
  // app logo or whatever UIImage you want to set in the center.
    let Logo = UIImage(named: "logo_which_you_want_to_set_in_the center_of_the_QRCode")!

    @IBOutlet weak var imgQRImage: UIImageView!

最后也是最后一步，将QRCode添加到imgQRImage中，并将代码放入您的imgQRImage中

override func viewDidLoad() {
    super.viewDidLoad()
    let QRLink = "https://www.peerbits.com/"
    guard let qrURLImage = URL(string: QRLink)?.qrImage(using: self.OrangeColor, logo: self.Logo)else{return}
    self.imgQRImage.image = UIImage(ciImage: qrURLImage)
}