Xamarin forms Android - Create Custom ListView divider from DataTemplate (Convert DataTemplate into Drawable)

Question

I am implementing a renderer for android ListView and i want to control the divider appearance. Therefore, i created a DataTemplate.

the problem is e.NewElement.SeperatorTemplate.CreateContent() returns View object.

and listView.Divider accepts Drawable object.

I need the conversion to be efficient so save it as an image is out of the question. Any ideas?

Ori Price Ori Price · Accepted Answer · 2016-06-29T11:16:07

Found a solution using view's drawing cache:

            //Convert Android view into Drawable

            view.DrawingCacheEnabled = true;
            view.Layout(0, 0, (int)Math.Round(request.Request.Width * Density), (int)Math.Round(request.Request.Height * Density));                  
            view.BuildDrawingCache(true);
            var bitmap = Bitmap.CreateBitmap(view.GetDrawingCache(true));
            view.DrawingCacheEnabled = false;
            Drawable drawable = new BitmapDrawable(bitmap);

Full code:

            //Get Xamarin forms view from DataTemplate
            Xamarin.Forms.View divider = (Xamarin.Forms.View)(e.NewElement.SeperatorTemplate?.CreateContent());
            if (divider != null)
            {
                //get renderer
                var dividerRenderer = Platform.CreateRenderer(divider);

                //Measuring the element
                SizeRequest request = dividerRenderer.Element.Measure(double.PositiveInfinity, double.PositiveInfinity);

                //Measuring element Chilren
                Xamarin.Forms.Layout.LayoutChildIntoBoundingRegion(dividerRenderer.Element, new Rectangle(0.0, 0.0, request.Request.Width, request.Request.Height));

                ViewGroup view = dividerRenderer.ViewGroup; 

                //Convert Android view into Drawable
                view.DrawingCacheEnabled = true;
                view.Layout(0, 0, (int)Math.Round(request.Request.Width * Density), (int)Math.Round(request.Request.Height * Density));    
                view.BuildDrawingCache(true);
                var bitmap = Bitmap.CreateBitmap(view.GetDrawingCache(true));
                view.DrawingCacheEnabled = false;

                //Set divider Drawable divider to native list divider
                listView.Divider = new BitmapDrawable(bitmap);
                listView.DividerHeight = (int)Math.Round(request.Request.Height * Density);
            }

Xamarin forms Android - Create Custom ListView divider from DataTemplate (Convert DataTemplate into Drawable)

1 Answers