how to create identifier on the fly-CodePudding

I my code, I have:

    public Bitmap loadIMG(Context context) {
        File pfile = getIMGPathFile(context);
        Bitmap bitmap = null;
        if (pfile.exists()) {
            try {
                //noinspection IOStreamConstructor
                bitmap = BitmapFactory.decodeStream(new FileInputStream(pfile));
            } catch (Exception e) {
                e.printStackTrace();
            }
        } else {
            @SuppressLint("DefaultLocale") String from = String.format(FILE_PROD_PREFIX   Consts.FILE_NUMERIC_FORMAT, mId);
            bitmap = BitmapFactory.decodeResource(context.getResources(), context.getResources().getIdentifier(from, "drawable", context.getPackageName()));
        }
        return bitmap;
    }

But I get a warning:

Use of this function is discouraged because resource reflection makes it harder to perform build optimizations and compile-time verification of code. It is much more efficient to retrieve resources by identifier (e.g. R.foo.bar) than by name (e.g. getIdentifier("bar", "foo", null)).

How can I modify my code with a minimum of side effects please?

CodePudding user response：

What are you doing with this bitmap? Do you actually need the bitmap, or is the Drawable sufficient? If you' just need the drawable, the entire code is:

context.getDrawable(R.id.filename);

There is almost NEVER a good reason to use decodeResources. Resources are preloaded into memory for fast access- they're already decoded. So you can just use them as a drawable. Generally if you're trying to load one of several drawables like you seem to by creating a parameterized path, you should be using assets instead of resources.

CodePudding user response：

One solution would be to have an array of identifiers, and use mId (or some other expression) as an index in that array:

static final int ids[] = {R.drawable.img1,R.drawable.img2,....};
...
bitmap = BitmapFactory.decodeResource(context.getResources(),ids[mId]);