dynamically getting all image resource id in an array

you can Use Reflection to achieve this.

import the Field class

import java.lang.reflect.Field;

and then write this in your code

Field[] ID_Fields = R.drawable.class.getFields();
int[] resArray = new int[ID_Fields.length];
for(int i = 0; i < ID_Fields.length; i++) {
    try {
        resArray[i] = ID_Fields[i].getInt(null);
    } catch (IllegalArgumentException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

resArray[] now holds references to all the drawables in your application.