My solution:Feel free to use.
NSArray *fieldz = [featureLayer fields];
NSString *neededField = @"FIELD_NAME";
for (int i = 0; i<[fieldz count]; i++)
{
AGSField *currentField = [fieldz objectAtIndex:i];
NSString *fieldName = currentField.name;
if ([fieldName isEqualToString:neededField])
{
NSArray *domains = [[currentField domain] codedValues];
if (domains)
{
NSLog(@"%@", currentField.name);
for (int a = 0; a < [domains count]; a++)
{
NSLog(@"NAME = %@ ; CODE = %@", [[domains objectAtIndex:a] name], [[domains objectAtIndex:a] code]);
}
}
NSLog(@"domain test complete");
}
}