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Session.FindObjectAsync(PersistentCriteriaEvaluationBehavior, XPClassInfo, CriteriaOperator, AsyncFindObjectCallback) Method

Asynchronously searches for the first object which matches the specified criteria, and notifies upon completion.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v19.2.dll

Declaration

public object FindObjectAsync(
    PersistentCriteriaEvaluationBehavior criteriaEvaluationBehavior,
    XPClassInfo classInfo,
    CriteriaOperator criteria,
    AsyncFindObjectCallback callback
)
Public Function FindObjectAsync(
    criteriaEvaluationBehavior As PersistentCriteriaEvaluationBehavior,
    classInfo As XPClassInfo,
    criteria As CriteriaOperator,
    callback As AsyncFindObjectCallback
) As Object
public object FindObjectAsync(
    PersistentCriteriaEvaluationBehavior criteriaEvaluationBehavior,
    XPClassInfo classInfo,
    CriteriaOperator criteria,
    AsyncFindObjectCallback callback
)
Public Function FindObjectAsync(
    criteriaEvaluationBehavior As PersistentCriteriaEvaluationBehavior,
    classInfo As XPClassInfo,
    criteria As CriteriaOperator,
    callback As AsyncFindObjectCallback
) As Object

Parameters

Name Type Description
criteriaEvaluationBehavior PersistentCriteriaEvaluationBehavior

A PersistentCriteriaEvaluationBehavior enumeration value that specifies how the persistent criteria is evaluated.

classInfo XPClassInfo

An XPClassInfo object which contains the metadata information of the class.

criteria CriteriaOperator

A CriteriaOperator descendant which represents the criteria to match persistent objects.

callback DevExpress.Xpo.Helpers.AsyncFindObjectCallback

A DevExpress.Xpo.Helpers.AsyncFindObjectCallback delegate to be called after the method completes.

Use callback to do the following:

  • Access the found object passed as the delegete's result parameter, or store it for later use within the original thread.
  • Store the exception information passed as delegete's ex parameter, and use this information later to raise the exception again, within the original thread.

Do not raise exceptions or modify persistent objects within a callback.

Parameters

Name Type Description
criteriaEvaluationBehavior PersistentCriteriaEvaluationBehavior

A PersistentCriteriaEvaluationBehavior enumeration value that specifies how the persistent criteria is evaluated.

classInfo XPClassInfo

An XPClassInfo object which contains the metadata information of the class.

criteria CriteriaOperator

A CriteriaOperator descendant which represents the criteria to match persistent objects.

callback DevExpress.Xpo.Helpers.AsyncFindObjectCallback

A DevExpress.Xpo.Helpers.AsyncFindObjectCallback delegate to be called after the method completes.

Use callback to do the following:

  • Access the found object passed as the delegete's result parameter, or store it for later use within the original thread.
  • Store the exception information passed as delegete's ex parameter, and use this information later to raise the exception again, within the original thread.

Do not raise exceptions or modify persistent objects within a callback.

Returns

Type Description
Object

An object used internally to manage an asynchronous operation.

Returns

Type Description
Object

An object used internally to manage an asynchronous operation.

Remarks

See Also