handle dispose in FormTask

WindowsFormsAppTask/WindowsFormsAppTask/Form1.Designer.cs

@@ -60,6 +60,8 @@
             this.Controls.Add(this.textBox1);
             this.Name = "Form1";
             this.Text = "Form1";
+            this.FormClosing += new System.Windows.Forms.FormClosingEventHandler(this.Form1_FormClosing);
+            this.Load += new System.EventHandler(this.Form1_Load);
             this.ResumeLayout(false);
             this.PerformLayout();
 

WindowsFormsAppTask/WindowsFormsAppTask/Form1.cs

@@ -19,12 +19,16 @@ namespace WindowsFormsAppTask
             InitializeComponent();
         }
 
+        private Task t;
+        private CancellationTokenSource cts;
+
         private void Button1_Click(object sender, EventArgs e)
         {
-            var t = new Task(DoIt);
+            cts = new CancellationTokenSource();
+            t = new Task(DoIt, cts.Token);
             t.Start();
 
-            for (int i = 0; i < 999; i++)
+            for (var i = 0; i < 999; i++)
             {
                 textBox1.Text += "-";
                 Application.DoEvents(); //update ui elements
@@ -37,24 +41,44 @@ namespace WindowsFormsAppTask
         {
             //Console.WriteLine(".");
 
-            for (int i = 0; i < 999; i++)
+            for (var i = 0; i < 999; i++)
             {
-                if (textBox1.InvokeRequired)
+                if (cts.IsCancellationRequested)
                 {
-                    textBox1.Invoke(new MethodInvoker(() => { textBox1.Text += "x"; }));
+                    return;
                 }
-                else
+                try
                 {
-                    textBox1.Text += "x";
+                    if (textBox1.InvokeRequired)
+                        textBox1.Invoke(new MethodInvoker(() => { textBox1.Text += "x"; }));
+                    else
+                        textBox1.Text += "x";
+                }
+                catch (ObjectDisposedException)
+                {
+                    return;
                 }
 
-                Random random = new Random();
+                Thread.Sleep(200);
-                Thread.Sleep(random.Next(100, 500));
             }
         }
 
         private void TextBox1_TextChanged(object sender, EventArgs e)
         {
         }
+
+        private void Form1_Load(object sender, EventArgs e)
+        {
+        }
+
+        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
+        {
+            cts.Cancel();
+
+            for (var i = 0; i < 999; i++)
+            {
+                var ii = 0;
+            }
+        }
     }
 }