All of the measurements have their own purposes: Use pixels for pixel-based things, like borders. You probably don’t want a border that ends up being 1.3422 pixels wide. Use text-centric measures (em, ex) for text-based things, like content areas, labels, and input boxes. It’s an easy way to make sure you have room for text … Read more
If you don’t have the exact size, there are two things that can happen: Upscaling @3x or @2x can be upscaled from @1x but usually the visual result is blurry, with thick lines and doesn’t look good. Upscaling @3x from @2x can be even worse because subpixels must be used. Downscaling In general, the results … Read more
It uses pixels, but I’m sure you’re wondering how to use dips instead. The answer is in TypedValue.applyDimension(). Here’s an example of how to convert dips to px in code: // Converts 14 dip into its equivalent px Resources r = getResources(); int px = Math.round(TypedValue.applyDimension( TypedValue.COMPLEX_UNIT_DIP, 14,r.getDisplayMetrics()));