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Project 16 : Adding a context menu to an image - image cache

Forums > 100 Days of SwiftUI

With the solution proposed for sharing, in front of the instruction: qrCode = UIImage(cgImage: cgimg) in the generateQRCode function, I get the error "Modifying state during view update, this will cause undefined behavior."

ChatGPT told me : The error you encounter, "Modifying state during view update, this will cause undefined behavior," occurs because you are modifying the state of your view (@State private var qrCode = UIImage()) directly in the generateQRCode(from) method. :) which is called while updating the view. In SwiftUI, it is important not to change the view state while SwiftUI is building or updating views, as this can cause unpredictable behaviors.

So I updated qrCode in the onChange() and onAppear() modifiers of the Form.

      .onAppear(){
           qrCode = generateQRCode(from: "\(name)\n\(emailAddress)")
      }

        .onChange(of: [name,emailAddress]) {
           qrCode = generateQRCode(from: "\(name)\n\(emailAddress)")
       }

Is there a better solution?

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