Question

I have an Array with integer values. It will grow over time. It will have approximately up to 50 values.
I want to store the array persistent and thus I thought about storing it in SharedPreferences.
I know that no complex types can be stored in it, but I also heard about to serialise the Array and then store it in SharedPreferences.
Can someone give me a hint or even better sample code how to do that?

Answer 1

Not very efficient way, but will get the job done:

SharedPreferences prefs = ...;
final int count = 50;
final String KEY_COUNT = "COUNT";
final String KEY_VAL_PREFIX = "VAL_";
int values[] = new int[count];

/*
 * ... put some stuff in values[] ...
 */

final Editor sped = prefs.edit();
sped.putInt(KEY_COUNT, count);
for (int i = 0; i < count; i++)
{
    sped.putInt(KEY_VAL_PREFIX + i, values[i]);
}
sped.commit();

Then later you can retrieve these values by grabbing the KEY_COUNT value from the prefs, then filling your empty array with values2[i] = getInt(KEY_VAL_PREFIX + i, 0) calls.