Cancellazione Task

WPFCatalog/MainWindowViewModel.cs

@@ -1,9 +1,11 @@
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using CatalogLib;
 using GalaSoft.MvvmLight.Command;
@@ -41,6 +43,7 @@ namespace WPFCatalog
         public RelayCommand OpenDestinationFolderCommand { get; private set; }
 
         public RelayCommand StartCommand { get; private set; }
+        public RelayCommand StopCommand { get; private set; }
 
         public RelayCommand PickFontCommand { get; private set; }
 
@@ -56,6 +59,8 @@ namespace WPFCatalog
             OpenDestinationFolderCommand = new RelayCommand(OpenDestinationFolder);
 
             StartCommand = new RelayCommand(Start);
+            StopCommand = new RelayCommand(Stop);
+
 
             PickFontCommand = new RelayCommand(PickFont);
         }
@@ -84,9 +89,11 @@ namespace WPFCatalog
             public bool Completed;
         }
 
+        private Task _workTask;
         //private List<ImageTask> _tasks;
         private async void Start()
         {
+            
             //Task outerTask = new Task(() =>
             //{
             //    Stopwatch s = new Stopwatch();
@@ -126,24 +133,58 @@ namespace WPFCatalog
             //    MaddoLogger.Log("Finished: {0}, {1}", s.Elapsed, s.ElapsedMilliseconds);
             //    DialogHelper.PopUpAlert($"Finished: {s.Elapsed}, {s.ElapsedMilliseconds}", "message");
             //});
+            if (/*_workTask == null || _workTask.IsCanceled || _workTask.IsCompleted || _workTask.IsFaulted*/!_isRunning)
+            {
+                _workTask = OuterTask();
+                try
+                {
+                    await _workTask;
+                }
+                catch (TaskCanceledException e)
+                {
+                    MaddoLogger.LogError(e);
+                    MaddoLogger.LogError("Master Task cancelled");
+                    //throw;
+                }
+                
+            }
 
-            Task outerTask = OuterTask();
-
-            await outerTask;
 
 
         }
 
+        
+
+        private void Stop()
+        {
+            if (_isRunning)
+            {
+                _tokenSource.Cancel();
+            }
+        }
+
+        private CancellationTokenSource _tokenSource;
+        private bool _isRunning = false;
         private async Task OuterTask()
         {
+            _isRunning = true;
+            _tokenSource = new CancellationTokenSource();
+            var token = _tokenSource.Token;
+            
+            var tasks = new ConcurrentBag<Task>();
+
+            IsUiActive = false;
             Stopwatch s = new Stopwatch();
 
-            var tasks = new List<Task>();
+            //var tasks = new List<Task>();
             // todo folder mode
             MaddoLogger.Log("Starting elaboration");
             var files = Directory.EnumerateFiles(PicSettings.DirectorySorgente).ToArray();
 
             TotalPictures = files.Count();
+
+            IImageProcessor i = new ImgSharpCreator();
+
             foreach (var file in files)
             {
                 //Task t = new Task(() =>
@@ -151,8 +192,8 @@ namespace WPFCatalog
 
                 //    //CompleteFile(file);
                 //});
-                var t = FileTask(file);
-
+                var t = FileTask(file, i, token);
+                
                 tasks.Add(t);
 
                 //_tasks.Add(new ImageTask() { ImageName = file, TaskImage = t, Completed = false });
@@ -165,24 +206,48 @@ namespace WPFCatalog
 
 
 
+            try
+            {
+                await Task.WhenAll(tasks);
+            }
+            catch (AggregateException e)
+            {
+                MaddoLogger.LogError(e);
+                MaddoLogger.LogError("Task cancelled");
+                //Console.WriteLine(e);
+                //Console.WriteLine("Task cancelled");
+                //throw;
+            }
+            finally
+            {
+                _tokenSource.Dispose();
 
-            await Task.WhenAll(tasks);
+                //Task.WhenAll(tasks).Start();
+                s.Stop();
+                //tt.RunSynchronously();
+                MaddoLogger.Log("Finished: {0}, {1}", s.Elapsed, s.ElapsedMilliseconds);
+                DialogHelper.PopUpAlert($"Finished: {s.Elapsed}, {s.ElapsedMilliseconds}", "message");
+
+                IsUiActive = true;
+                _isRunning = false;
+            }
+            
 
 
 
-            //Task.WhenAll(tasks).Start();
-            s.Stop();
-            //tt.RunSynchronously();
-            MaddoLogger.Log("Finished: {0}, {1}", s.Elapsed, s.ElapsedMilliseconds);
-            DialogHelper.PopUpAlert($"Finished: {s.Elapsed}, {s.ElapsedMilliseconds}", "message");
+            
         }
 
 
-        private async Task FileTask(string file)
+        private async Task FileTask(string file, IImageProcessor i, CancellationToken token)
         {
+            if (token.IsCancellationRequested == true)
+            {
+                token.ThrowIfCancellationRequested();
+            }
             MaddoLogger.Log("Starting task for image {0}", file);
-            IImageProcessor i = new ImgSharpCreator();
-            await Task.Run(() => i.Start(new FileInfo(file)));
+            //IImageProcessor i = new ImgSharpCreator();
+            await Task.Run(() => i.Start(new FileInfo(file)), token);
             CurrentImage = file;
             TotalPictures--;
         }
@@ -265,6 +330,13 @@ namespace WPFCatalog
 
         #region Proprietà
 
+        private bool _isUiActive = true;
+        public bool IsUiActive
+        {
+            get => _isUiActive;
+            set { _isUiActive = value; RaisePropertyChanged("IsUiActive"); }
+        }
+
         private string _currentImage;
 
         public string CurrentImage