Question

I have a custom folder, file and custom XML resource class in my “res” folder.

I create some custom objects, which I call:

<area id="@+id/someId" name="Some Name" />

I can access them statically by R.id.someId.

However, I need to get the resource id at runtime and I need to do that by the “name”. In other words, I display that “Some Name” in the list and I need to get the id of knowing that the user selected “Some Name” from the ListView. (I am NOT looking for the id of the ListItem, I actually want to search my resources and get the id of the area xml object)

For example:

I would like to do something of the following:

int id = getIdFromResourceName("Some Name"); 

Is this possible?

I have tried using:

int i = this.getResources().getIdentifier("Some Name", "area", this.getPackageName());

…but that did not seem to work. I always get 0.

EDIT

As suggested below by Geobits, is there a way to load all of the resources from a res file and save them in an array/map, such as Map<id,name> so I can search them later?

Thank you for the help!

Answer 1

I am not sure if this is what you need. But here is my solution proposal. This is how I would do it, if your resource was a drawable:

    public int findResourceIdByName(String name) {
        Field[] fields = R.drawable.class.getFields();  // get all drawables
        try {
            for(int i=0; i<fields.length; i++) {        // loop through all drawable resources in R.drawable
                int curResId = fields[i].getInt(R.drawable.class); // Returns the value of the field in the specified object as an int.
                                                                  //This reproduces the effect of object.fieldName

                Drawable drawable = getResources().getDrawable(R.drawable.icon); // get the Drawable object
                if(drawable.getName().equals(name)) {   //getName() is NOT possible for drawable, this is just an example
                    return curResId;                    // return the corresponding resourceId
                                                        // or you could return the drawable object instead, 
                                                        // depending on what you need.
                }
            }

            return -1; // no ResourceId found for this name

        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
    }

This is using Reflection, so it won’t be the most efficient approach. If you call this method frequently, you might need to cache the result of

Field[] fields = R.drawable.class.getFields();

at least.