How to fetch a R id in Java using a variable name

Question

ImageView test = (ImageView) findViewById(R.id.A1);

gets me an ImageView

instead of A1 I would like to use a string variable to fetch a series of IDs

I have tried

Method Pmethod = Class.getDeclaredMethod("(ImageView) findViewById(Id.R." + dest.toString());

as suggusted in this question : how to call a java method using a variable name?

However I get the error

non-static method getDeclaredMethod cannot be referenced from a static context

Any way to fix this?

My latest attempt :

        String ps = "P"+ dest.toString();
        String ss = "S"+ dest.toString();
        int piecelayertier = getResources().getIdentifier(ps,"id","com.donthaveawebsite.mhy.ocfix");
        int selectorlayertier = getResources().getIdentifier(ss,"id","com.donthaveawebsite.mhy.ocfix");
        ImageView test =(ImageView)findViewById(piecelayertier);

        spot.TieAppearance((ImageView)findViewById(piecelayertier));
        spot.TieSelector((ImageView)findViewById(selectorlayertier));

That's not how R works, and that's not how getDeclaredMethod works either. See the accepted answer to this question for more help with R: http://stackoverflow.com/questions/6804053/understand-the-r-class-in-android Since you have to do the work of defining the ids in your xml code, why do you need a dynamically generated list? As to getDeclaredMethod, the exception is exactly correct. You're trying to call it as if it's a static method. It's hard to tell what you want here and why you want it. — mttdbrd, Apr 29 '15 at 04:46
@mttdbrd any idea why the ints aren't setting? The ps and ss strings are correctly populated and the resources exist. — M Y, Apr 29 '15 at 05:24

score 2 · Accepted Answer · edited Apr 29 '15 at 06:19

2

I think this is not a correct way to get id.

You can try following to get id using a string variable :

int id = getResources().getIdentifier("<String id>","id","<package name>");
ImageView test =(ImageView)findViewById(id);

You might also need to use a this reference like so :

int id = this.getResources().getIdentifier("<String id>","id", getPackageName());

edited Apr 29 '15 at 06:19

M Y

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answered Apr 29 '15 at 04:37

Sachin Gupta

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This is almost what I need, except 'int id' is not getting set. – M Y Apr 29 '15 at 05:19
@hellyale are you getting any exception, since its working for me . – Sachin Gupta Apr 29 '15 at 05:35
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It may be possible that package name is wrong , you can call `getPackageName()` method to get the desired package name. – Sachin Gupta Apr 29 '15 at 05:40

How to fetch a R id in Java using a variable name

1 Answers1