迅速生成一个二维码 [英] swift generate a qrcode

问题描述

我试图生成一个二维码，但是有错误

I tried to generate a qrcode, but it has error

线程1:致命错误:在展开可选值时意外发现nil

Thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value

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

推荐答案

我使用了以下代码，并且运行良好.self.imgQRCode是要在其上显示QR的图像视图.

I have used the following code, and it is working perfectly.Where self.imgQRCode is the imageview on which you want to display QR.

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
    }

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