I am making image form QR Code by using following code:
func createQRFromString(str: String) -> CIImage? {
let stringData = str.dataUsingEncoding(NSUTF8StringEncoding)
let filter = CIFilter(name: "CIQRCodeGenerator")
filter?.setValue(stringData, forKey: "inputMessage")
filter?.setValue("H", forKey: "inputCorrectionLevel")
return filter?.outputImage
}
And Then I am adding to UIImageView Like this:
if let img = createQRFromString(strQRData) {
let somImage = UIImage(CIImage: img, scale: 1.0, orientation: UIImageOrientation.Down)
imgviewQRcode.image = somImage
}
Now I need to save this to a JPEG or PNG file. But when I am doing so my app crashes:
@IBAction func btnSave(sender: AnyObject) {
// // Define the specific path, image name
let documentsDirectoryURL = try! NSFileManager().URLForDirectory(.DocumentDirectory, inDomain: .UserDomainMask, appropriateForURL: nil, create: true)
// create a name for your image
let fileURL = documentsDirectoryURL.URLByAppendingPathComponent("image.jpg")
if let image = imgviewQRcode.image // imgviewQRcode is UIImageView
{
if let path = fileURL?.path
{
if !NSFileManager.defaultManager().fileExistsAtPath(fileURL!.path!)
{
if UIImageJPEGRepresentation(image, 1.0)!.writeToFile(path, atomically: true)
{
print("file saved")
}
}//Checking existing file
}//Checking path
}//CHecking image
}
Crash Point
UIImageJPEGRepresentation(image, 1.0)!.writeToFile(path, atomically: true)
Reason
fatal error: unexpectedly found nil while unwrapping an Optional value
Debug Tests:
Shemona
func convert(cmage:CIImage) -> UIImage
{
let context:CIContext = CIContext.init(options: nil)
let cgImage:CGImage = context.createCGImage(cmage, from: cmage.extent)!
let image:UIImage = UIImage.init(cgImage: cgImage)
return image
}
Use this function to convert CIImage to UIImage . It works .
My final code
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) {
let context:CIContext = CIContext.init(options: nil)
let cgImage:CGImage = context.createCGImage(output, from: output.extent)!
let image:UIImage = UIImage.init(cgImage: cgImage)
return image
}
}
return nil
} func convert(image:CIImage) -> UIImage
{
let image:UIImage = UIImage.init(ciImage: image)
return image
}
Perhaps, this was unavailable before, but it is now possible to create UIImages directly from CIImage.
来源：https://stackoverflow.com/questions/40939075/unable-to-convert-ciimage-to-uiimage-in-swift-3-0