Управление текущей задачей переосмыслено через enum TaskState. Удалены неиспользуемые using *.

fileFinder/MainForm.cs

@@ -1,14 +1,7 @@
 using System;
-using System.Collections.Generic;
-using System.ComponentModel;
-using System.Data;
 using System.Drawing;
-using System.Linq;
-using System.Text;
 using System.Threading.Tasks;
 using System.Windows.Forms;
-using System.IO;
-using System.Threading;
 using System.Timers;
 
 namespace fileFinder
@@ -19,6 +12,7 @@ namespace fileFinder
         TaskController mainController = new TaskController();
         SearchQueryModel searchQueryModel;
         System.Timers.Timer updateInfoTimer = new System.Timers.Timer(1000);
+        bool isFieldsChanged = false;
 
         public MainForm()
         {
@@ -38,7 +32,7 @@ namespace fileFinder
             queryTextBox.Text = sets.fileNameQuery;
             searchQueryModel = mainController.updateSearchQueryModel(sets.fileUrl,
                 sets.fileInnerQuery, sets.fileNameQuery);
-            mainController.isTaskChanged = false;
+            isFieldsChanged = false;
         }
 
         private void fillImagesToResultViewer()
@@ -81,10 +75,15 @@ namespace fileFinder
     
         private void reportProgress(object sender, ProgressReportModel report)
         {
-            if (!mainController.isPaused)
+            switch (mainController.state)
+            {
+                case TaskState.Work:
                     updateInfoLabel(report.currentFileUrl, report.progress);
-            else if (mainController.isPaused)
+                    break;
+                case TaskState.Pause:
                     updateResultViewer(report.currentTreeNode);
+                    break;
+            }
         }
 
         private async void handleSearchBtn_Click(object sender, EventArgs e)
@@ -92,10 +91,13 @@ namespace fileFinder
             Progress<ProgressReportModel> progress = new Progress<ProgressReportModel>();
             progress.ProgressChanged += reportProgress;
 
-            if (mainController.isStopped || mainController.isTaskChanged)
+            if (isFieldsChanged)                // если в форме изменился запрос
+                mainController.stopTask();      // то принудительно завершаем задание
+            isFieldsChanged = false;
+
+            switch (mainController.state)
             {
-                mainController.stopTask();
-                mainController = new TaskController();
+                case TaskState.Created:
                     searchQueryModel = mainController.updateSearchQueryModel(curDirTextBox.Text,
                         queryTextBox.Text, innerQueryTextBox.Text);
                     handleSearchBtn.Text = "Pause Task";
@@ -105,32 +107,38 @@ namespace fileFinder
                     if (tN != null)
                     {
                         updateResultViewer(tN);
-                    changeVisibilityResultViewer();
                         handleSearchBtn.Text = "Start Task";
                     }
-            } else if (mainController.isPaused)
-            {
-                handleSearchBtn.Text = "Pause Task";
-                mainController.resumeTask();
-                changeVisibilityResultViewer();
-            } else
-            {
+                    break;
+                case TaskState.Work:
                     handleSearchBtn.Text = "Resume Task";
                     mainController.pauseTask();
-                changeVisibilityResultViewer();
+                    break;
+                case TaskState.Pause:
+                    handleSearchBtn.Text = "Pause Task";
+                    mainController.resumeTask();
+                    break;
+                case TaskState.Finished:
+                    mainController = new TaskController();
+                    goto case TaskState.Created;
             }
+            changeVisibilityResultViewer();
         }
 
         private void changeVisibilityResultViewer()
         {
-            if (mainController.isStopped || mainController.isPaused)
-            {
-                waitOrPauseLabel.Visible = false;
-                resultViewer.Enabled = true;
-            } else
+            switch (mainController.state)
             {
+                case TaskState.Work:                // если задание в работе, то блокируем ResultViewer
                     waitOrPauseLabel.Visible = true;
                     resultViewer.Enabled = false;
+                    break;
+                case TaskState.Pause:   // если задание на паузе, то показываем промеж. результат
+                    waitOrPauseLabel.Visible = false;
+                    resultViewer.Enabled = true;
+                    break;
+                case TaskState.Finished:            // если задание завершено, то показываем результат
+                    goto case TaskState.Pause;
             }
         }
         
@@ -189,9 +197,9 @@ namespace fileFinder
 
         private void changeTaskBtnStatus()
         {
-            if (!mainController.isTaskChanged)
+            if (!isFieldsChanged)
             {
-                mainController.isTaskChanged = true;
+                isFieldsChanged = true;
                 handleSearchBtn.Text = "Start New Task";
             }
         }

fileFinder/ProgressReportModel.cs

@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using System.Windows.Forms;
+using System.Windows.Forms;
 
 namespace fileFinder
 {

fileFinder/TaskController.cs

@@ -6,63 +6,46 @@ using System.Linq;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
-using System.Timers;
 using System.Windows.Forms;
 
 namespace fileFinder
 {
+    public enum TaskState { Created, Work, Pause, Finished }
     class TaskController
     {
-        public bool isPaused { get; private set; }
-        public bool isStopped { get; private set; }
-        public bool isFormUpdatedAfterPause { get; set; }
-        public bool isTaskChanged { get; set; }
         private Stopwatch stopwatch = new Stopwatch();
+        public TaskState state { get; private set; }
 
-        public TaskController ()
+        public TaskController()
         {
-            isPaused = false;
-            isStopped = true;
-            isFormUpdatedAfterPause = true;
-            isTaskChanged = false;
+            state = TaskState.Created;
         }
 
-        public void beginTask ()
+        public void beginTask()
         {
-            isPaused = false;
-            isStopped = false;
+            state = TaskState.Work;
             stopwatch.Restart();
         }
 
-        public void pauseTask ()
+        public void pauseTask()
         {
-            if (!isPaused && !isStopped)
-            {
-                isPaused = true;
-                isFormUpdatedAfterPause = false;
+            state = TaskState.Pause;
             stopwatch.Stop();
         }
-        }
         
-        public void resumeTask ()
+        public void resumeTask()
         {
-            if (isPaused && !isStopped)
-            {
-                isPaused = false;
+            state = TaskState.Work;
             stopwatch.Start();
         }
-        }
 
-        public void stopTask ()
+        public void stopTask()
         {
-            if (!isStopped)
-            {
-                isStopped = true;
+            state = TaskState.Finished;
             stopwatch.Stop();
         }
-        }
 
-        public TimeSpan elapsedTime ()
+        public TimeSpan elapsedTime()
         {
             return stopwatch.Elapsed;
         }
@@ -77,21 +60,19 @@ namespace fileFinder
             int counter = 0;
             foreach (string item in foundFiles)
             {
-                if (controller.isStopped)
-                    return null;
-                while (controller.isPaused)
-                {
-                    Thread.Sleep(100);
-                    if (!controller.isFormUpdatedAfterPause)
+                switch (state)
                 {
-                        controller.isFormUpdatedAfterPause = true;
+                    case TaskState.Finished:
+                        return null;
+                    case TaskState.Pause:   
                         _report.progress = counter;
                         _report.currentFileUrl = item;
                         _report.currentTreeNode = (TreeNode)itemsNode.Clone();
                         report.Report(_report);
-                    }
-                }
-
+                        while (state == TaskState.Pause)   
+                            Thread.Sleep(100);
+                        goto case TaskState.Work;
+                    case TaskState.Work:
                         string[] fileLines = getFileContents(item);
                         _report.progress = counter;
                         _report.currentFileUrl = item;
@@ -102,6 +83,8 @@ namespace fileFinder
                             counter++;
                             await fillChildNode(itemsNode, item.Replace(query.fileUrl, ""));
                         }
+                        break;
+                }
             }
             controller.stopTask();
             return itemsNode;