private void Button_Click(object sender, RoutedEventArgs e)
        {
            Button btn = sender as Button;
            string tag = btn.Tag.ToString().ToLower();

            switch (tag)
            {
            case "create": Operator = Operation.Create; break;

            case "move": Operator = Operation.Move; break;

            case "modify":
                Operator = Operation.Modify;
                break;

            case "delete": Operator = Operation.Delete; break;

            case "clsall":

                SQliteDbContext.DeleteAllExPin((App.Current.Resources["Locator"] as ViewModelLocator).ExcelPaper.Fixture.FixtureType);
                (App.Current.Resources["Locator"] as ViewModelLocator).ExcelPaper.Pins.Clear();
                foreach (var item in canvas.Children)
                {
                    try
                    {
                        if (item is Ellipse)
                        {
                            var ep = item as Ellipse;
                            canvas.UnregisterName(ep.Name);
                        }
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                    }
                }
                this.canvas.Children.Clear();
                break;

            case "clear":
                (App.Current.Resources["Locator"] as ViewModelLocator).ExcelPaper.Channels.Clear(); break;

            default:
                break;
            }
        }