Where did these borders come from in Monogame Android?

Question

Even when I use GraphicsDevice.ToggleFullScreen() or GraphicsDevice.IsFullScreen = true; followed by GraphicsDevice.ApplyChanges() as described in this post, I still seem to have this border on both edges of the screen, shown in classic CornflowerBlue for contrast in this screenshot. The background image is anchored at 0,0 with width and height set to the dimensions of the screen. The "borders" seem to be about 10 or 20px from what I can guess, and not at the top or bottom, only at the left and right edges. I can't understand where this is coming from.

Answer 1

If you want your game to be at full screen of every device:

#if ANDROID
            graphics.IsFullScreen = true;                
            graphics.PreferredBackBufferWidth = GraphicsAdapter.DefaultAdapter.CurrentDisplayMode.Width;
            graphics.PreferredBackBufferHeight = GraphicsAdapter.DefaultAdapter.CurrentDisplayMode.Height;
            graphics.SupportedOrientations = DisplayOrientation.Portrait;//if your game does NOT support for anything else but portrait mode
            graphics.ApplyChanges();
#endif

However, in this case, you need to be careful because the ratio of devices are different, some are 16:9, some are 4:3, etc. If you need your game to be adapt to all of them, you better adjust the sizes of your game objects to be changeable or set them to be proportional.