Session.PreFetch(XPClassInfo, IEnumerable, String[]) Method

Enforces loading data for associated collections and delayed properties.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v24.1.dll

NuGet Packages: DevExpress.Win.PivotGrid, DevExpress.Win.TreeMap, DevExpress.Xpo

NuGet Package: DevExpress.Xpo

Declaration

C#

public void PreFetch(
    XPClassInfo classInfo,
    IEnumerable objects,
    params string[] propertyPaths
)

VB.NET

Public Sub PreFetch(
    classInfo As XPClassInfo,
    objects As IEnumerable,
    ParamArray propertyPaths As String()
)

Parameters

Name	Type	Description
classInfo	XPClassInfo	An XPClassInfo object that provides metadata information for a parent class.
objects	IEnumerable	An IEnumerable list of parent objects.
propertyPaths	String[]	An array of strings that are the collection property and delayed property names, or property paths (e.g, “ChildCollection.AnotherChildCollection”).

Remarks

By default, data is loaded automatically when you access a nested collection or delayed property for the first time. When the PreFetch method is called, all data for the specified collections and delayed properties is loaded at once. No additional SQL queries for this data will be performed later.

C#

using DevExpress.Xpo;
// ...
XPCollection<Person> people = new XPCollection<Person>(session);
session.PreFetch(session.GetClassInfo<Person>(), people, nameof(PhoneNumbers));

VB.NET

Imports DevExpress.Xpo
' ...
Dim people As New XPCollection(Of Person)(session)
session.PreFetch(session.GetClassInfo(Of Person)(), people, NameOf(PhoneNumbers)))

If you specify a property path, the PreFetch method loads every delayed property that exists in the specified path.