[英]iOS CoreNFC - class "NFTechnologyEvent" not loaded or does not exist
嘗試使用 iPhone 7 Plus 讀取 NFC 標簽時出現此錯誤
2017-12-13 14:03:01.522137-0300 nfc[279:9534] [general] 連接到名為 com.apple.nfcd.service.corenfc 的服務:在解碼接收到的消息時捕獲異常,丟棄傳入消息。
異常:解碼參數 0 時出現異常(調用的 #2):
異常:decodeObjectForKey:類“NFTechnologyEvent”未加載或不存在
我有適當的權利( Near Field Communication Tag Reading
)和Privacy - NFC Scan Usage Description
設置。
要重現它,只需啟動一個新的單視圖項目並用以下內容替換默認的ViewController
:
import UIKit
import CoreNFC
class ViewController: UIViewController, NFCNDEFReaderSessionDelegate {
// Reference the NFC session
private var nfcSession: NFCNDEFReaderSession!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.startScanning()
}
func startScanning() {
// Create the NFC Reader Session when the app starts
self.nfcSession = NFCNDEFReaderSession(delegate: self, queue: nil, invalidateAfterFirstRead: false)
// A custom description that helps users understand how they can use NFC reader mode in your app.
self.nfcSession?.alertMessage = "Macri Gato"
self.nfcSession?.begin()
}
// Called when the reader-session expired, you invalidated the dialog or accessed an invalidated session
public func readerSession(_ session: NFCNDEFReaderSession, didInvalidateWithError error: Error) {
print("NFC-Session invalidated: \(error.localizedDescription)")
print("==========================")
self.startScanning()
}
// Called when a new set of NDEF messages is found
public func readerSession(_ session: NFCNDEFReaderSession, didDetectNDEFs messages: [NFCNDEFMessage]) {
print("New NFC Messages (\(messages.count)) detected:")
print(messages)
}
}
在開始 nfcSession 之前,您必須檢查 NFCNDEFReaderSession.readingAvailable true 以便繼續 session.begin() 方法。
還要確保將“隱私 - NFC 掃描使用說明”添加到 Info.plist
@IBAction func beginScanning(_ sender: Any) {
guard NFCNDEFReaderSession.readingAvailable else {
let alertController = UIAlertController(
title: "Scanning Not Supported",
message: "This device doesn't support tag scanning.",
preferredStyle: .alert
)
alertController.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
self.present(alertController, animated: true, completion: nil)
return
}
session = NFCNDEFReaderSession(delegate: self, queue: nil, invalidateAfterFirstRead: false)
session?.alertMessage = "Hold your iPhone near the item to learn more about it."
session?.begin()
}
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