Session.GetObjectByKeyAsync<ClassType>(Object, Boolean, CancellationToken) Method

Asynchronously returns a persistent object that has the specified key property value. The persistent object’s type is set by the generic type parameter.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v23.2.dll

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

NuGet Package: DevExpress.Xpo

Declaration

C#

public Task<ClassType> GetObjectByKeyAsync<ClassType>(
    object id,
    bool alwaysGetFromDataStore,
    CancellationToken cancellationToken = default(CancellationToken)
)

VB.NET

Public Function GetObjectByKeyAsync(Of ClassType)(
    id As Object,
    alwaysGetFromDataStore As Boolean,
    cancellationToken As CancellationToken = Nothing
) As Task(Of ClassType)

Parameters

Name	Type	Description
id	Object	An object that represents the persistent object’s key property value.
alwaysGetFromDataStore	Boolean	true, to always reload the persistent object from storage even if it is found in memory; otherwise, false.

Optional Parameters

Name	Type	Default	Description
cancellationToken	CancellationToken	null	A CancellationToken object that delivers a cancellation notice to the running operation.

Type Parameters

Name	Description
ClassType	A type of objects to search for.

Returns

Type	Description
Task<ClassType>	A Task that returns a persistent object from a data store. This persistent object has the specified key property value and a type specified by the generic type parameter. The task returns null if no objects are found.

Remarks

Below is an example of using the GetObjectByKeyAsync<ClassType> method. Here, the session is the Session instance.

C#

using System.Threading;
using DevExpress.Xpo;
// ...
CancellationTokenSource source = new CancellationTokenSource();
CancellationToken cancellationToken = source.Token;
Person personToDelete = await session.GetObjectByKeyAsync<Person>(152, true, cancellationToken);
session.Delete(personToDelete);

VB.NET

Imports System.Threading
Imports DevExpress.Xpo
' ...
Private source As New CancellationTokenSource()
Private cancellationToken As CancellationToken = source.Token
Private personToDelete As Person = Await session.GetObjectByKeyAsync(Of Person)(152, True, cancellationToken)
session.Delete(personToDelete)

The GetObjectByKeyAsync<ClassType> method searches the memory for the object with the specified key property value. If such an object is found, it is not reloaded. To get the up-to-date object from the data store, the alwaysGetFromDataStore parameter must be set to true.