Migrated the project to dotnet core 3.0

src/Sample Project/Tutorials/02 - ToolTips/UserControlToolTipWindow.xaml.cs

@@ -0,0 +1,23 @@
+using System.Windows;
+
+namespace Samples.Tutorials.ToolTips
+{
+    /// <summary>
+    /// Interaction logic for UserControlToolTipWindow.xaml
+    /// </summary>
+    public partial class UserControlToolTipWindow : Window
+    {
+        public UserControlToolTipWindow()
+        {
+            InitializeComponent();
+        }
+
+        protected override void OnClosing(System.ComponentModel.CancelEventArgs e)
+        {
+            //clean up notifyicon (would otherwise stay open until application finishes)
+            MyNotifyIcon.Dispose();
+
+            base.OnClosing(e);
+        }
+    }
+}