Implementing a way to catch uncaught exceptions

calculatorUICOOP.Android/Helpers/LogLevel.cs

@@ -0,0 +1,11 @@
+namespace calculatorUICOOP.Droid.Helpers
+{
+    public enum LogLevel
+    {
+        Verbose = 0,
+        Debug = 1,
+        Information = 2,
+        Warning = 3,
+        Error = 4
+    }
+}

calculatorUICOOP.Android/Helpers/Logger.cs

@@ -0,0 +1,42 @@
+using System;
+using System.IO;
+
+using Android.App;
+
+namespace calculatorUICOOP.Droid.Helpers
+{
+    public class Logger
+    {
+        /// <value>
+        /// Gets the log file.
+        /// </value>
+        private readonly FileInfo _logFile;
+
+        public Logger()
+        {
+            // Generate Log Directory
+            const string LOG_DIRECTORY_NAME = "logs";
+            var PRIVATE_EXTERNAL_STORAGE = Application.Context.GetExternalFilesDir(null);
+            var logDir = new DirectoryInfo(Path.Combine(PRIVATE_EXTERNAL_STORAGE.AbsolutePath, LOG_DIRECTORY_NAME));
+
+            if (!logDir.Exists)
+                logDir.Create();
+
+            // Set Log File
+            string logFileName = $"{DateTime.UtcNow:s}.log";
+            var logFile = new FileInfo(Path.Combine(logDir.FullName, logFileName));
+
+            _logFile = logFile;
+        }
+
+        public void Log(LogLevel level, string message)
+        {
+            using var log = _logFile.Exists ? _logFile.AppendText() : _logFile.CreateText();
+
+            log.WriteLine($"[{DateTime.UtcNow:s}] ({level}) - {message}");   // [2020-12-24T21:30:00] (INFO) - Ho Ho Ho! Merry Log Message
+        }
+
+        public void Log(LogLevel level, Exception exception) =>
+            Log(level, $"Exception: {exception.Message}{Environment.NewLine}{exception.StackTrace}");
+    }
+}

calculatorUICOOP.Android/MainActivity.cs

@@ -1,17 +1,20 @@
-using System;
+using calculatorUICOOP.Droid.Helpers;
+using System;
+using System.Linq;
+using System.Threading.Tasks;
 
 using Android.App;
 using Android.Content.PM;
-using Android.Runtime;
-using Android.Views;
-using Android.Widget;
 using Android.OS;
+using Android.Runtime;
 
 namespace calculatorUICOOP.Droid
 {
     [Activity(Label = "calculatorUICOOP", Icon = "@mipmap/icon", Theme = "@style/MainTheme", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
     public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
     {
+        private Logger _logger;
+
         protected override void OnCreate(Bundle savedInstanceState)
         {
             TabLayoutResource = Resource.Layout.Tabbar;
@@ -22,12 +25,29 @@ protected override void OnCreate(Bundle savedInstanceState)
             Xamarin.Essentials.Platform.Init(this, savedInstanceState);
             global::Xamarin.Forms.Forms.Init(this, savedInstanceState);
             LoadApplication(new App());
+
+            // Handling uncaught application exceptions
+            _logger = new Logger();
+            AppDomain.CurrentDomain.UnhandledException += CurrentDomainOnUnhandledException;
+            TaskScheduler.UnobservedTaskException += TaskSchedulerOnUnobservedTaskException;
         }
         public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults)
         {
             Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);
 
             base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
         }
+        #region Handling uncaught application exceptions
+        private void CurrentDomainOnUnhandledException(object sender, UnhandledExceptionEventArgs unhandledExceptionEventArgs)
+        {
+            var exception = unhandledExceptionEventArgs.ExceptionObject as Exception;
+            _logger.Log(LogLevel.Error, exception);
+        }
+        private void TaskSchedulerOnUnobservedTaskException(object sender, UnobservedTaskExceptionEventArgs unobservedTaskExceptionEventArgs)
+        {
+            foreach (var exception in unobservedTaskExceptionEventArgs.Exception.InnerExceptions)
+                _logger.Log(LogLevel.Error, exception);
+        }
+        #endregion
     }
 }

calculatorUICOOP.Android/calculatorUICOOP.Android.csproj

@@ -58,6 +58,8 @@
     <PackageReference Include="Xamarin.Essentials" Version="1.3.1" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Helpers\Logger.cs" />
+    <Compile Include="Helpers\LogLevel.cs" />
     <Compile Include="MainActivity.cs" />
     <Compile Include="Resources\Resource.designer.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />