我正在尝试通过CoreNFC框架读取NFC标签，但出现错误。已经尝试使用以下代码
import UIKit
import CoreNFC
class ViewController: UIViewController, NFCNDEFReaderSessionDelegate {
@IBOutlet weak var messageLabel: UILabel!
var nfcSession: NFCNDEFReaderSession?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
@IBAction func scanPressed(_ 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
}
nfcSession = NFCNDEFReaderSession(delegate: self, queue: nil, invalidateAfterFirstRead: true)
nfcSession?.alertMessage = "Hold your iPhone near the item to learn more about it."
nfcSession?.begin()
}
func readerSession(_ session: NFCNDEFReaderSession, didInvalidateWithError error: Error) {
// Check the invalidation reason from the returned error.
if let readerError = error as? NFCReaderError {
// Show an alert when the invalidation reason is not because of a
// successful read during a single-tag read session, or because the
// user canceled a multiple-tag read session from the UI or
// programmatically using the invalidate method call.
if (readerError.code != .readerSessionInvalidationErrorFirstNDEFTagRead)
&& (readerError.code != .readerSessionInvalidationErrorUserCanceled) {
let alertController = UIAlertController(
title: "Session Invalidated",
message: error.localizedDescription,
preferredStyle: .alert
)
alertController.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
DispatchQueue.main.async {
self.present(alertController, animated: true, completion: nil)
}
}
}
// To read new tags, a new session instance is required.
self.nfcSession = nil
}
func readerSessionDidBecomeActive(_ session: NFCNDEFReaderSession) {
print ("readerSessionDidBecomeActive")
}
func readerSession(_ session: NFCNDEFReaderSession, didDetectNDEFs messages: [NFCNDEFMessage]) {
// Parse the card's information
/*
( // Payload one (There's only one payload in this card)
"TNF=1, /* Type Name Format */
Payload Type=<55>,
Payload ID=<>,
Payload=<0048656c 6c6f21>" /* What we're really interested in */
)
*/
var result = ""
for payload in messages[0].records {
result += String.init(data: payload.payload.advanced(by: 3), encoding: .utf8)! // 1
}
DispatchQueue.main.async {
self.messageLabel.text = result
}
}
}
控制台日志：
Started scanning for tags
2019-12-30 17:35:33.709179+0530 nfcTest[2492:251252] [xpc.exceptions] <NSXPCConnection: 0x281c92e20> connection to service on pid 82 named com.apple.nfcd.service.corenfc: Exception caught during decoding of received selector didDetectExternalReaderWithNotification:, dropping incoming message.
Exception: Exception while decoding argument 0 (#2 of invocation):
Exception: decodeObjectForKey: class "NFFieldNotification" not loaded or does not exist
(
0 CoreFoundation 0x000000018c7e5820 FF63481D-FB6A-353B-B2C1-AC4EAECF594D + 1226784
1 libobjc.A.dylib 0x000000018c50dfa4 objc_exception_throw + 56
2 Foundation 0x000000018ccd1390 3C682044-3249-3938-8111-F2F12D066D2B + 2339728
3 Foundation 0x000000018caaa4e4 3C682044-3249-3938-8111-F2F12D066D2B + 83172
4 Foundation 0x000000018ccf35dc 3C682044-3249-3938-8111-F2F12D066D2B + 2479580
5 Foundation 0x000000018caff62c 3C682044-3249-3938-8111-F2F12D066D2B + 431660
6 Foundation 0x000000018caff994 3C682044-3249-3938-8111-F2F12D066D2B + 432532
7 Foundation 0x000000018cae9d70 3C682044-3249-3938-8111-F2F12D066D2B + 343408
8 Foundation 0x000000018cccf1bc 3C682044-3249-3938-8111-F2F12D066D2B + 2331068
9 libxpc.dylib 0x000000018c3b3448 219DEC3C-E62E-395D-8911-FB74F73A5598 + 50248
10 libxpc.dylib 0x000000018c3b37c0 219DEC3C-E62E-395D-8911-FB74F73A5598 + 51136
11 libdispatch.dylib 0x0000000100d4ec98 _dispatch_client_callout4 + 16
12 libdispatch.dylib 0x0000000100d68aa8 _dispatch_mach_msg_invoke + 420
13 libdispatch.dylib 0x0000000100d55990 _dispatch_lane_serial_drain + 304
14 libdispatch.dylib 0x0000000100d698f8 _dispatch_mach_invoke + 520
15 libdispatch.dylib 0x0000000100d55990 _dispatch_lane_serial_drain + 304
16 libdispatch.dylib 0x0000000100d56718 _dispatch_lane_invoke + 500
17 libdispatch.dylib 0x0000000100d61adc _dispatch_workloop_worker_thread + 1324
18 libsystem_pthread.dylib 0x000000018c502f88 _pthread_wqthread + 276
19 libsystem_pthread.dylib 0x000000018c505ad4 start_wqthread + 8
)
(
0 CoreFoundation 0x000000018c7e5820 FF63481D-FB6A-353B-B2C1-AC4EAECF594D + 1226784
1 libobjc.A.dylib 0x000000018c50dfa4 objc_exception_throw + 56
2 Foundation 0x000000018ccf3828 3C682044-3249-3938-8111-F2F12D066D2B + 2480168
3 Foundation 0x000000018caff62c 3C682044-3249-3938-8111-F2F12D066D2B + 431660
4 Foundation 0x000000018caff994 3C682044-3249-3938-8111-F2F12D066D2B + 432532
5 Foundation 0x000000018cae9d70 3C682044-3249-3938-8111-F2F12D066D2B + 343408
6 Foundation 0x000000018cccf1bc 3C682044-3249-3938-8111-F2F12D066D2B + 2331068
7 libxpc.dylib 0x000000018c3b3448 219DEC3C-E62E-395D-8911-FB74F73A5598 + 50248
8 libxpc.dylib 0x000000018c3b37c0 219DEC3C-E62E-395D-8911-FB74F73A5598 + 51136
9 libdispatch.dylib 0x0000000100d4ec98 _dispatch_client_callout4 + 16
10 libdispatch.dylib 0x0000000100d68aa8 _dispatch_mach_msg_invoke + 420
11 libdispatch.dylib 0x0000000100d55990 _dispatch_lane_serial_drain + 304
12 libdispatch.dylib 0x0000000100d698f8 _dispatch_mach_invoke + 520
13 libdispatch.dylib 0x0000000100d55990 _dispatch_lane_serial_drain + 304
14 libdispatch.dylib 0x0000000100d56718 _dispatch_lane_invoke + 500
15 libdispatch.dylib 0x0000000100d61adc _dispatch_workloop_worker_thread + 1324
16 libsystem_pthread.dylib 0x000000018c502f88 _pthread_wqthread + 276
17 libsystem_pthread.dylib 0x000000018c505ad4 start_wqthread + 8
)
Session did invalidate with error: Error Domain=NFCError Code=202 "Session invalidated unexpectedly" UserInfo={NSLocalizedDescription=Session invalidated unexpectedly}
参考链接：
任何帮助，我们将不胜感激。预先感谢。
您是否在plist文件中授予权限？
隐私-NFC扫描使用说明