AFSearch(T).FindObjectIds Method

public override IEnumerable<Guid> FindObjectIds(
	int startIndex = 0,
	int pageSize = 0
)

// Get the Database
PISystems myPISystems = new PISystems();
PISystem myPISystem = myPISystems.DefaultPISystem;
if (myPISystem == null)
    throw new InvalidOperationException("Default PISystem was not found.");
AFDatabase myDB = myPISystem.Databases[dbName];
if (myDB == null)
    throw new InvalidOperationException("Database was not found.");

// Use attribute value query to find a list of tanks that are 
// In Service (tanks which are out-of-service have their 
// Status attribute set to "OS").
int totalCount = 0;
using (var search = new AFElementSearch(myDB, "FindTanks", @"Template:'TankAdvanced' |Status:<>'OS'"))
{
    search.CacheTimeout = TimeSpan.FromMinutes(10);

    // Because we are only going to use a few of the attributes for each
    // of the elements found, we can reduce the load time and memory space
    // by just loading the attributes we need.  Note that if we inadvertently
    // use attributes other than these, we will incur a load penalty.
    AFElementTemplate tankTemplate = myDB.ElementTemplates["Tank"];
    AFNamedCollectionList<AFAttributeTemplate> myAttributes =
        new AFNamedCollectionList<AFAttributeTemplate>();
    myAttributes.Add(tankTemplate.AttributeTemplates["Volume"]);
    myAttributes.Add(tankTemplate.AttributeTemplates["Level"]);
    myAttributes.Add(tankTemplate.AttributeTemplates["Level|HighLimit"]);
    myAttributes.Add(tankTemplate.AttributeTemplates["Level|LowLimit"]);

    // Get today's date and UOMs to be used for converting values.
    AFTime today = new AFTime("T", CultureInfo.CurrentCulture);
    UOM bbl = myDB.PISystem.UOMDatabase.UOMs["bbl"];
    UOM meter = myDB.PISystem.UOMDatabase.UOMs["m"];

    const int pageSize = 1000;
    int startIndex = 0;
    IList<Guid> myElementIds = new List<Guid>(pageSize);
    do
    {
        // Find the element IDs and load the attributes we will be using.
        var results = search.FindObjectIds(startIndex, pageSize: pageSize);
        myElementIds.Clear();
        int c = 0;
        foreach (Guid id in results)
        {
            totalCount++;
            myElementIds.Add(id);
            c++;
            if (c >= pageSize)
                break;
        }

        if (myElementIds.Count == 0) break;
        AFNamedCollectionList<AFElement> elements =
            AFElement.LoadAttributes(myPISystem, myElementIds, myAttributes);

        // Once the elements are loaded, we can process them.
        foreach (AFElement element in elements)
        {
            try
            {
                AFAttributeList attributes = new AFAttributeList();
                attributes.Add(element.Attributes["Volume"]);
                attributes.Add(element.Attributes["Level"]);
                attributes.Add(element.Attributes["Level|HighLimit"]);
                attributes.Add(element.Attributes["Level|LowLimit"]);
                AFValues values = attributes.GetValue(today);

                if (values[0].IsGood && values[1].IsGood &&
                    values[2].IsGood && values[3].IsGood)
                {
                    double volume = (double)values[0].Convert(bbl).Value;
                    double level = (double)values[1].Convert(meter).Value;
                    double high = (double)values[2].Convert(meter).Value;
                    double low = (double)values[3].Convert(meter).Value;

                    Console.WriteLine("Tank Inventory for '{0}' is {1} bbl.  %Full={2}",
                        element.Name, volume, 100 * (high - low) / level);
                }
                else
                {
                    Console.WriteLine("Bad data in Tank '{0}'", element.Name);
                }
            }
            catch (FormatException)
            {
                Console.WriteLine("Error in Tank '{0}'", element.Name);
            }
        }

        startIndex += myElementIds.Count; // Advance to next page.
    } while (myElementIds.Count > 0 && myElementIds.Count >= pageSize);
}

Console.WriteLine("Processed {0} Elements.", totalCount);