Windows 8 Metro App - Render PNGs

Question

I am needing to render some custom PNGs in a Windows 8 app.

Basically I need to create a custom live tile by putting some drawings made in my app on top of an image for a live tile, and the only way to do this is render a PNG to disk, see here.

What library should I use to do this? My first thought was to use a Xaml UserControl and RenderTargetBitmap, but it is not available in a Metro app.

Answer 1

WinRT XAML Toolkit has some extension methods for WriteableBitmap that you could use too. You could probably use WriteableBitmapLoadExtensions for loading and WriteableBitmapSaveExtensions for saving. It has a fairly limited blitting capability though since that is exposed by WriteableBitmapEx already and simple to write anyway. WriteableBitmapBlitBlockExtensions is only a method to blit a full width block of pixels from bitmaps of same width.

Edit* RenderTargetBitmap is now available in Windows 8.1. It doesn't support some elements though (I think it doesn't render camera previews, media elements and perhaps WebViews).

Answer 2

Currently the only option is to use DirectX (or SharpDX) to create your image. You'll probably have to recreate the drawing using the low-level DirectX APIs. WritableBitmapEx might also be helpful if your drawings are simple.