swift生成qrcode[重复]

Question

我试图生成一个qrcode，但它有错误

线程1：致命错误：在展开一个可选值时意外地找到nil

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

我已经使用了下面的代码，它工作得很好。其中self.imgqrcode是您希望在其上显示QR的imageview。

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
    }