ZXing.Net.Mobile.Forms.ZXingDefaultOverlay.ZXingDefaultOverlay C# (CSharp) Method

        public ZXingDefaultOverlay ()
        {
            VerticalOptions = LayoutOptions.FillAndExpand;
            HorizontalOptions = LayoutOptions.FillAndExpand;

            RowDefinitions.Add (new RowDefinition { Height = new GridLength (1, GridUnitType.Star) });
            RowDefinitions.Add (new RowDefinition { Height = new GridLength (2, GridUnitType.Star) });
            RowDefinitions.Add (new RowDefinition { Height = new GridLength (1, GridUnitType.Star) });
            ColumnDefinitions.Add (new ColumnDefinition { Width = new GridLength (1, GridUnitType.Star) });


            Children.Add (new BoxView {
                VerticalOptions = LayoutOptions.Fill,
                HorizontalOptions = LayoutOptions.FillAndExpand,
                BackgroundColor = Color.Black,
                Opacity = 0.7,
            }, 0, 0);

            Children.Add (new BoxView {
                VerticalOptions = LayoutOptions.Fill,
                HorizontalOptions = LayoutOptions.FillAndExpand,
                BackgroundColor = Color.Black,
                Opacity = 0.7,
            }, 0, 2);

            Children.Add (new BoxView {
                VerticalOptions = LayoutOptions.Center,
                HorizontalOptions = LayoutOptions.FillAndExpand,
                HeightRequest = 3,
                BackgroundColor = Color.Red,
                Opacity = 0.6,
            }, 0, 1);

            topText = new Label {
                VerticalOptions = LayoutOptions.Center,
                HorizontalOptions = LayoutOptions.Center,
                TextColor = Color.White,
                AutomationId = "zxingDefaultOverlay_TopTextLabel",
            };
            topText.SetBinding( Label.TextProperty, new Binding( nameof( TopText ) ) );
            Children.Add (topText, 0, 0);

            botText = new Label {
                VerticalOptions = LayoutOptions.Center,
                HorizontalOptions = LayoutOptions.Center,
                TextColor = Color.White,
                AutomationId = "zxingDefaultOverlay_BottomTextLabel",
            };
            botText.SetBinding( Label.TextProperty, new Binding( nameof( BottomText ) ) );
            Children.Add (botText, 0, 2);

            flash = new Button {
                HorizontalOptions = LayoutOptions.End,
                VerticalOptions = LayoutOptions.Start,
                Text = "Flash",
                TextColor = Color.White,
                AutomationId = "zxingDefaultOverlay_FlashButton",
            };
            flash.SetBinding( Button.IsVisibleProperty, new Binding( nameof( ShowFlashButton ) ) );
            flash.Clicked += (sender, e) => {
                FlashButtonClicked?.Invoke( flash, e );
            };

            Children.Add (flash, 0, 0);
        }