如何制作不同屏幕尺寸的图像？

Question

Getting my head around Android, I've sort of trouble understanding support for multiple devices. I've gone through the dev-docu, now for the clear-up:

The idea behind using dp is, that eg a button has the same 'real-world'-size, independent of the actual screen-size, right? If so, that means, I provide the images in ldpi, hdpi and so on. That results in a button, that has always the same size. If still correct, I understand that now, that my buttons always has the same size, I should provide different layouts, because on a small device, there might only be space for two next to one another, where on a larger device there's room for three.

If all of the above is correct, my question would be, how I deal graphics-tool-wise with it. Say I have a button 100px x 100px at 300dpi, what sizes and dpi's would that be for the new documents in eg Gimp for the different screensizes?

Thanx in advance for any smoke-lifting! Marcus

Answer 1

What it means when you can use your custom assets for different screen densities is that when you put those respective assets, they will not scale again and use them as they are. Now it is true that the size of the screen also varies. That is when you can consider tweaking your layout.

For example in a large screen you may be able to fit two components beside each other and use a linear layout with horizontal alignment. But when it comes to a small screen, that might not be possible and one option is to define a new layout for small screens and say pt those two components in a vertical layout.

For more information regarding how to implement this and best practices, check these Android Docs

Answer 2

After some more study, it seems that the graphocs-tools DPI are actually the one referred to in eg the baseline. So to create a baseline-doc, you indeed create a document 470 x 320 pixel in size and a resolution of 160 dpi. The rest goes from there.