diff --git a/App.xaml.cs b/App.xaml.cs
index 1f49957..619ecb8 100644
--- a/App.xaml.cs
+++ b/App.xaml.cs
@@ -122,7 +122,10 @@ public static void Quit(bool savesetting)
             foreach (var win in MainWindows)
             {
                 if (win == null) continue;
-                win.SaveToXamlPkg();
+                var exMsg = win.SaveToXamlPkg();
+                if (exMsg != null &&
+                    MessageBox.Show(exMsg + "\r\n" + (string)App.Current.Resources["msgbox_not_saved_confirm"], "", MessageBoxButton.YesNo, MessageBoxImage.Exclamation) != MessageBoxResult.Yes)
+                    return;
                 if (savesetting)
                 {
                     win.CurrentSetting.Win_Pos = new Point(win.Left, win.Top);
diff --git a/MainWindow.xaml b/MainWindow.xaml
index f03b930..3670dda 100644
--- a/MainWindow.xaml
+++ b/MainWindow.xaml
@@ -26,7 +26,8 @@
         </Rectangle>
         <RichTextBox x:Name="RTB_Main" Margin="20" Background="{x:Null}" BorderBrush="{x:Null}" AcceptsTab="True" BorderThickness="0" IsInactiveSelectionHighlightEnabled="True"
                      TextChanged="RTB_Main_TextChanged" PreviewKeyDown="RTB_Main_PreviewKeyDown" PreviewMouseWheel="RTB_Main_PreviewMouseWheel"
-                     LostKeyboardFocus="RTB_Main_LostKeyboardFocus" ContextMenuOpening="RTB_Main_ContextMenuOpening" PreviewMouseDown="RTB_Main_PreviewMouseDown">
+                     GotKeyboardFocus="RTB_Main_GotKeyboardFocus" LostKeyboardFocus="RTB_Main_LostKeyboardFocus"
+                     ContextMenuOpening="RTB_Main_ContextMenuOpening" PreviewMouseDown="RTB_Main_PreviewMouseDown">
             <!--<wtk:RichTextBoxFormatBarManager.FormatBar>
                 <wtk:RichTextBoxFormatBar/>
             </wtk:RichTextBoxFormatBarManager.FormatBar>-->
diff --git a/MainWindow.xaml.cs b/MainWindow.xaml.cs
index bd0c8f8..50c2524 100644
--- a/MainWindow.xaml.cs
+++ b/MainWindow.xaml.cs
@@ -270,6 +270,11 @@ private void RTB_Main_LostKeyboardFocus(object sender, KeyboardFocusChangedEvent
                 DockToSide();
         }
 
+        private void RTB_Main_GotKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
+        {
+            App.FormatWindow.UpdateTargets(this);
+        }
+
         private void RTB_Main_ContextMenuOpening(object sender, ContextMenuEventArgs e)
         {
             e.Handled = true;
@@ -338,60 +343,43 @@ private void SaveNotes()
             }
         }
 
-        internal void SaveToXamlPkg()
+        private string TextRangeSave()
         {
-            lock (Lock_Save)
+            string statusText, exMsg = null;
+            try
             {
-                TextRange tr = null;
-                bool isUIthread = Dispatcher.CheckAccess();
-                string result;
-                if (isUIthread)
-                    tr = new TextRange(RTB_Main.Document.ContentStart, RTB_Main.Document.ContentEnd);
-                else
-                    Dispatcher.Invoke(delegate { tr = new TextRange(RTB_Main.Document.ContentStart, RTB_Main.Document.ContentEnd); });
-
-                try
-                {
-                    if (isUIthread)
-                    {
-                        using (var ms = new FileStream(CurrentSetting.Doc_Location, FileMode.Create))
-                        {
-                            tr.Save(ms, DataFormats.XamlPackage, true);
-                        }
-                        File.WriteAllText(CurrentSetting.Bak_Location, tr.Text);
-                    }
-                    else
-                    {
-                        Dispatcher.Invoke(delegate
-                        {
-                            using (var ms = new FileStream(CurrentSetting.Doc_Location, FileMode.Create))
-                            {
-                                tr.Save(ms, DataFormats.XamlPackage, true);
-                            };
-                            File.WriteAllText(CurrentSetting.Bak_Location, tr.Text);
-                        });
-                    }
-                    result = (string)Application.Current.Resources["status_saved"];
-                }
-                catch
+                var tr = new TextRange(RTB_Main.Document.ContentStart, RTB_Main.Document.ContentEnd);
+                using (var ms = new FileStream(CurrentSetting.Doc_Location, FileMode.Create))
                 {
-                    result = (string)Application.Current.Resources["status_save_failed"];
+                    tr.Save(ms, DataFormats.XamlPackage, true);
                 }
+                File.WriteAllText(CurrentSetting.Bak_Location, tr.Text);
+                statusText = (string)Application.Current.Resources["status_saved"];
+            }
+            catch (Exception ex)
+            {
+                statusText = (string)Application.Current.Resources["status_save_failed"];
+                exMsg = ex.ToString();
+            }
+
+            TB_Status.Text = statusText;
+            TB_Status.Visibility = Visibility.Visible;
+            return exMsg;
+        }
 
+        /// <returns>Non-null string if there are errors when saving.</returns>
+        internal string SaveToXamlPkg()
+        {
+            string exMsg = null;
+            lock (Lock_Save)
+            {
+                bool isUIthread = Dispatcher.CheckAccess();
                 if (isUIthread)
-                {
-                    TB_Status.Text = result;
-                    TB_Status.Visibility = Visibility.Visible;
-                }
+                    exMsg = TextRangeSave();
                 else
-                {
-                    Dispatcher.Invoke(delegate
-                    {
-                        TB_Status.Text = result;
-                        TB_Status.Visibility = Visibility.Visible;
-                    });
-                }
+                    exMsg = Dispatcher.Invoke(() => TextRangeSave());
             }
+            return exMsg;
         }
 
         private void Win_Main_Loaded(object sender, RoutedEventArgs e)
@@ -583,8 +571,8 @@ private void TrayIcon_TrayMouseDoubleClick(object sender, RoutedEventArgs e)
                 win.UnDock();
             }
         }
-        #endregion
 
+        #endregion
 
     }
 }
diff --git a/Resources/StringResources.en.xaml b/Resources/StringResources.en.xaml
index fd64b72..35ce4a6 100644
--- a/Resources/StringResources.en.xaml
+++ b/Resources/StringResources.en.xaml
@@ -59,4 +59,5 @@ Program will exit now.</sys:String>
     <sys:String x:Key="label_content_path_txt">Text content path</sys:String>
     <sys:String x:Key="menu_newnote">New Note</sys:String>
     <sys:String x:Key="msgbox_delete_confirm">Do you also want to delete the note content and backup files?</sys:String>
+    <sys:String x:Key="msgbox_not_saved_confirm">Current note content is not saved. Changes will be lost after exiting. Exit anyway?</sys:String>
 </ResourceDictionary>
\ No newline at end of file
diff --git a/Resources/StringResources.zh.xaml b/Resources/StringResources.zh.xaml
index d6dd852..99df3d9 100644
--- a/Resources/StringResources.zh.xaml
+++ b/Resources/StringResources.zh.xaml
@@ -59,4 +59,5 @@
     <sys:String x:Key="label_content_path_txt">文本保存路径</sys:String>
     <sys:String x:Key="menu_newnote">新笔记</sys:String>
     <sys:String x:Key="msgbox_delete_confirm">是否需要一起删除笔记内容和备份文件？</sys:String>
+    <sys:String x:Key="msgbox_not_saved_confirm">当前笔记内容并未保存，退出会丢失更改的内容。确定要退出吗？</sys:String>
 </ResourceDictionary>
\ No newline at end of file
diff --git a/bin/Release/DesktopNote.exe b/bin/Release/DesktopNote.exe
index 620c401..ec72550 100644
Binary files a/bin/Release/DesktopNote.exe and b/bin/Release/DesktopNote.exe differ