Batch getting many bitmap resources on Android

Question

I have a long series of graphics -- icon1_0.png, icon1_1.png, icon1_2.png..., icon12_0.png, icon12_1.png, icon12_2.png -- and I'd like to package them with my android application. Ideally I think I should be able to load them as resources but the resource id's are set up as java identifiers. Of course, java identifiers can't be assembled at runtime. I have to ask for R.drawable.icon12_00 so I cannot set up a loop

for(int icon=0;icon<12;icon++)
 for(int frame=0;frame<3;frame++)
  //syntax error obviously
  BitmapFactory.decodeResource(getResources(), R.drawable."icon" + icon + "_" + frame + ".png");

So is there any way to get resources by their names? Better yet, is there a canonical way outside the resource system to pack data files into an android application package so that I can get at them?

I'm thinking about reflection but that doesn't seem like the right solution to me.

score 13 · Accepted Answer · answered Jan 24 '10 at 22:20

13

Use getResources().getIdentifier() from your Context (e.g., Activity), but please cache the result if you will use it more than once. getIdentifier() is implemented on Resources.

answered Jan 24 '10 at 22:20

CommonsWare

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Okay, this works. getIdentifier("resname", "restype", "com.domain.appname"); Thank you. – Brian Jan 24 '10 at 22:51
1

Instead passing package name as static value, you can use `getPackageName()` – Paresh Mayani Jan 05 '12 at 09:11

score 6 · Answer 2 · answered Jan 25 '10 at 01:01

6

I know you've found an answer already, but if you use reflection then you will see a good speed increase, as getIdentifier() is slower. I wrote about how to do the reflection method here. However, this only works if you're accessing your own resources.

answered Jan 25 '10 at 01:01

Dan Lew

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How about that. This is a little faster. It's a shame, though, because reflection is notoriously pokey so getIdentifier must be monster slow. – Brian Jan 26 '10 at 02:56

score 2 · Answer 3 · answered Jan 25 '10 at 08:10

2

Reflection is also very slow, you should just create an array with all of your identifies in it.

answered Jan 25 '10 at 08:10

Romain Guy

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Do you mean, just write the whole loop out in code? Or something more clever? I'd be interested in the latter, because it would be a nice speed boost if I could get a resource even faster than using reflection (but this would be in a slightly different circumstance, where app data refers to resources - not in code). – Dan Lew Jan 25 '10 at 17:08
@DanielLew he is saying you have a code generator which writes the whole loop out in code for you – Pacerier Feb 17 '12 at 00:59

Batch getting many bitmap resources on Android

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