如何处理屏幕尺寸和密度的多种组合？

Question

I'm struggling with getting the right drawables onto the right screen. I followed the android developer instructions and created a version per drawable for ldpi through xxhdpi . However, physically small and large screens with the same dpi select the same drawable , where I'd like the larger screen to get a bigger one.

The layouts are pretty straight forward, so I don't think I need to create new ones with different qualifiers, so I need to come up with a good way to categorise drawables (and/or screen resolutions). I'm guessing it's done with the sw<N>dp qualifier or one of it's siblings, but how do I choose the intervals? I've seen examples ( sw600dp , w820dp , etc) but no guidelines for how to determine them. Do I need to do it by trial-and-error on different AVD configurations, and which are the best to do so with?

How do I scale my drawables when I've determined which -sw<N>dp to use? Do I follow the standard 3:4:6:8:12:16 or something else?

Yet again, the sw<N>dp qualifiers don't seem to be for drawables , since they get scaled weirdly and blurry as a result. Do I instead use layouts with the qualifiers, but how? I'm really at a loss here...

Answer 1

However, physically small and large screens with the same dpi select the same drawable, where I'd like the larger screen to get a bigger one.

Put the smaller ones in res/drawable-...dpi/ directories, for varying values of ... (eg, x ). Put the larger ones in res/drawable-swNNNdp-...dpi/ , for varying values of NNN (eg, 800 ) and ... . Note that the -swNNNdp qualifier has to be in the name before the -...dpi qualifier.

but how do I choose the intervals?

That's up to you. You are the one who is saying that "I'd like the larger screen to get a bigger one". Only you know what you like, and only you know where the cutoff is between "larger" and not-"larger" is in your mind. There is no universal answer for this, just as there is no universal answer for when you change the layout of a Web page to be "mobile" or not.

Do I need to do it by trial-and-error on different AVD configurations, and which are the best to do so with?

I would recommend that you try it on hardware.

If you decide that you want larger images on 7" tablets and up, -sw600dp would be a reasonable choice. If you decide that you want larger images on 10" tablets and up, -sw720dp would be a reasonable choice. Beyond that, break out a ruler and measure the shortest screen width, then multiply by 160 to get dpi. Google also maintains a database of many popular devices , with the dimensions in px and dpi for each.

How do I scale my drawables when I've determined which -swdp to use?

Again, that's up you. If you decide that you want the images to be 50% bigger on the larger screens, create your images that are 50% bigger. Again, you are the one who is saying "I'd like the larger screen to get a bigger one". Only you know what you like, and only you know what "bigger" would mean to get you to something that you like.