Login, NFCWaiter

2025-03-24 14:02:25 +01:00
parent d55dee91e9
commit ebe33abf69
11 changed files with 308 additions and 62 deletions
@@ -0,0 +1,117 @@
+using Plugin.NFC;
+using System.Collections.ObjectModel;
+
+namespace WorkFlowCheck.MAUI.Pages.NFC;
+
+public partial class NFCWaiter : ContentPage
+{
+
+    private bool _eventsAlreadySubscribed = false;
+    private bool _onReceiveing = false;
+    private TaskCompletionSource<string> _taskCompletionSource;
+
+    public NFCWaiter(TaskCompletionSource<string> taskCompletionSource)
+    {
+        InitializeComponent();
+        _taskCompletionSource = taskCompletionSource;
+    }
+    protected override async void OnAppearing()
+    {
+        base.OnAppearing();
+
+        CrossNFC.Legacy = false;
+        if (CrossNFC.IsSupported)
+        {
+            if (!CrossNFC.Current.IsAvailable)
+                await ShowAlert("NFC is not available");
+
+            if (!CrossNFC.Current.IsEnabled)
+                await ShowAlert("NFC is disabled");
+
+            await AutoStartAsync().ConfigureAwait(false);
+        }
+        else
+        {
+            await ShowAlert("NFC is not available");
+        }
+
+    }
+    async Task AutoStartAsync()
+    {
+        // Some delay to prevent Java.Lang.IllegalStateException "Foreground dispatch can only be enabled when your activity is resumed" on Android
+        await Task.Delay(500);
+        await StartListeningIfNotiOS();
+    }
+    async Task StartListeningIfNotiOS()
+    {
+
+        await BeginListening();
+    }
+    async Task BeginListening()
+    {
+        try
+        {
+            MainThread.BeginInvokeOnMainThread(() =>
+            {
+                SubscribeEvents();
+                CrossNFC.Current.StartListening();
+            });
+        }
+        catch (Exception ex)
+        {
+            await ShowAlert(ex.Message);
+        }
+    }
+    async Task EndListening()
+    {
+        try
+        {
+            MainThread.BeginInvokeOnMainThread(() =>
+            {
+                UnsubscribeEvents();
+                CrossNFC.Current.StopPublishing();
+                CrossNFC.Current.StopListening();
+
+            });
+        }
+        catch (Exception ex)
+        {
+            await ShowAlert(ex.Message);
+        }
+    }
+    void SubscribeEvents()
+    {
+        if (_eventsAlreadySubscribed)
+            UnsubscribeEvents();
+
+        _eventsAlreadySubscribed = true;
+
+        CrossNFC.Current.OnMessageReceived += Current_OnMessageReceived_NFCData;
+
+
+    }
+    void UnsubscribeEvents()
+    {
+        CrossNFC.Current.OnMessageReceived -= Current_OnMessageReceived_NFCData;
+        _eventsAlreadySubscribed = false;
+    }
+    async void Current_OnMessageReceived_NFCData(ITagInfo tagInfo)
+    {
+        _onReceiveing = true;
+        if (tagInfo == null)
+        {
+            await ShowAlert("No tag found");
+            _onReceiveing = false;
+            return;
+        }
+
+        // Customized serial number
+        var identifier = tagInfo.Identifier;
+        var serialNumber = NFCUtils.ByteArrayToHexString(identifier, ":");
+        _taskCompletionSource.TrySetResult(serialNumber);
+        await EndListening();
+        await Navigation.PopAsync();
+        _onReceiveing = false;
+    }
+    Task ShowAlert(string message, string title = null) => DisplayAlert(string.IsNullOrWhiteSpace(title) ? "NFC olvasás" : title, message, "OK");
+}