Hey again, I recently asked about updating a variable but now have a new problem. I am creating an NFC reader which when I press scan it prints the UID (Unique Identifier) of the NFC in a text field. When the button labeled "Scan" is pressed, the function activate() runs which activates the NFC reader and updates a variable within the NFCReader class called tagUID to the UID of the NFC chip. After activate() the button then changes tagCode to equal tagUID. The problem is that I want it to update only after the NFCTagReaderSession ends, as it only updates it to the previous UID scanned right now as it did not finish scanning before I update the variable. How do I do this? The code is below:
struct ContentView: View {
let reader: NFCReader = NFCReader()
@State var tagCode = "UID"
var body: some View {
VStack{
Text(tagCode)
Button {
reader.activate()
tagCode = reader.tagUID
} label: {
Text("Scan")
.font(.title)
}.padding()
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
class NFCReader: NSObject, ObservableObject, NFCTagReaderSessionDelegate {
var tagUID = "UID"
var session: NFCTagReaderSession?
func activate() {
self.session = NFCTagReaderSession(pollingOption: .iso14443, delegate: self)
self.session?.alertMessage = "Hold Your Phone Near the NFC Tag"
self.session?.begin()
}
func tagReaderSessionDidBecomeActive(_ session: NFCTagReaderSession) {
print("Session Begun!")
}
func tagReaderSession(_ session: NFCTagReaderSession, didInvalidateWithError error: Error) {
print("Error with Launching Session")
}
func tagReaderSession(_ session: NFCTagReaderSession, didDetect tags: [NFCTag]) {
print("Connecting To Tag")
if tags.count > 1{
session.alertMessage = "More Than One Tag Detected, Please try again"
session.invalidate()
}
let tag = tags.first!
session.connect(to: tag) { [self] (error) in
if nil != error{
session.invalidate(errorMessage: "Connection Failed")
}
if case let .miFare(sTag) = tag{
let UID = sTag.identifier.map{ String(format: "%.2hhx", $0)}.joined()
print("UID:", UID)
print(sTag.identifier)
session.alertMessage = "UID Captured"
session.invalidate()
DispatchQueue.main.async {
self.tagUID = "\(UID)"
}
}
}
}
}
