老周：當RichEditBox控件的上下文菜單即將彈出時，會引發ContextMenuOpening事件，我們需要處理該事件，并且將e.Handled屬性設置為true，這樣才能阻止默認上下文菜單的彈出 在RichEditBox控件上聲明附加的菜單項 ~~~ <RichEditBox Name="redit" Grid.Row="3" Margin="10,10,10,10" ContextMenuOpening="OnContextMenuOpening"> <FlyoutBase.AttachedFlyout> <MenuFlyout> <MenuFlyoutItem Text="復制" Click="OnCopy"/> <MenuFlyoutItem Text="剪切" Click="OnCut"/> <MenuFlyoutItem Text="粘貼" Click="OnPaste"/> <MenuFlyoutSeparator/> <MenuFlyoutSubItem Text="字號"> <MenuFlyoutItem Text="16" Tag="16" Click="OnFontSize" /> <MenuFlyoutItem Text="20" Tag="20" Click="OnFontSize"/> <MenuFlyoutItem Text="24" Tag="24" Click="OnFontSize" /> <MenuFlyoutItem Text="36" Tag="36" Click="OnFontSize"/> <MenuFlyoutItem Text="48" Tag="48" Click="OnFontSize"/> </MenuFlyoutSubItem> <!--分割--> <MenuFlyoutSeparator/> <ToggleMenuFlyoutItem Text="加粗" Click="OnBold" /> <MenuFlyoutSeparator/> <MenuFlyoutSubItem Text="下劃線"> <MenuFlyoutItem Text="無" Tag="-1" Click="OnUnderline" /> <MenuFlyoutItem Text="單實線" Tag="0" Click="OnUnderline"/> <MenuFlyoutItem Text="雙實線" Tag="1" Click="OnUnderline"/> <MenuFlyoutItem Text="虛線" Tag="2" Click="OnUnderline"/> </MenuFlyoutSubItem> <MenuFlyoutSeparator/> <MenuFlyoutSubItem Text="顏色"> <MenuFlyoutItem Text="黑色" Tag="黑色" Click="OnTinct"/> <MenuFlyoutItem Text="藍色" Tag="藍色" Click="OnTinct"/> <MenuFlyoutItem Text="白色" Tag="白色" Click="OnTinct"/> </MenuFlyoutSubItem> </MenuFlyout> </FlyoutBase.AttachedFlyout> </RichEditBox> ~~~ 處理OnContextMenuOpening ~~~ private void OnContextMenuOpening(object sender , ContextMenuEventArgs e) { //阻止彈出默認的上下文菜單，然后，調用ShowAt方法在指定的坐標處打開菜單 e.Handled = true; MenuFlyout menu = FlyoutBase.GetAttachedFlyout(redit) as MenuFlyout; menu?.ShowAt(redit , new Point(e.CursorLeft , e.CursorTop)); } ~~~ 處理復制粘貼 ~~~ private void OnCopy(object sender , RoutedEventArgs e) { //復制 redit.Document.Selection.Copy(); } private void OnCut(object sender , RoutedEventArgs e) { //剪切 redit.Document.Selection.Cut(); } private void OnPaste(object sender , RoutedEventArgs e) { //粘貼 redit.Document.Selection.Paste(0); //Paste 要在粘貼操作中使用的剪貼板格式。零表示最佳格式 } ~~~ 處理OnFontSize ~~~ /// <summary> /// 設置字體 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void OnFontSize(object sender , RoutedEventArgs e) { MenuFlyoutItem item = sender as MenuFlyoutItem; // 獲取字號 float size = Convert.ToSingle(item.Tag); redit.Document.Selection.CharacterFormat.Size = size; } ~~~ ~~~ /// <summary> /// 加粗 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void OnBold(object sender , RoutedEventArgs e) { //using Windows.UI.Text; ToggleMenuFlyoutItem item = sender as ToggleMenuFlyoutItem; redit.Document.Selection.CharacterFormat.Bold = item.IsChecked ? FormatEffect.On : FormatEffect.Off; } private void OnUnderline(object sender , RoutedEventArgs e) { MenuFlyoutItem item = sender as MenuFlyoutItem; int x = Convert.ToInt32(item.Tag); UnderlineType unlinetp; switch (x) { case -1: // 無 unlinetp = UnderlineType.None; break; case 0: // 單實線 unlinetp = UnderlineType.Single; break; case 1: // 雙實線 unlinetp = UnderlineType.Double; break; case 2: // 虛線 unlinetp = UnderlineType.Dash; break; default: unlinetp = UnderlineType.None; break; } redit.Document.Selection.CharacterFormat.Underline = unlinetp; } ~~~ ~~~ private void OnTinct(object sender , RoutedEventArgs e) { MenuFlyoutItem item = sender as MenuFlyoutItem; string tinct = item.Tag as string; Windows.UI.Color color = new Windows.UI.Color(); switch (tinct) { case "黑色": color= Windows.UI.Colors.Black; break; case "藍色": color = Windows.UI.Colors.Blue; break; case "白色": color = Windows.UI.Colors.White; break; default: break; } redit.Document.Selection.CharacterFormat.BackgroundColor = color; } ~~~ 顏色在Windows.UI.Color 里面代碼都是抄老周的  參考：[http://www.cnblogs.com/tcjiaan/p/4937301.html](http://www.cnblogs.com/tcjiaan/p/4937301.html)