IDataLayerAsync Interface

Declares asynchronous methods for data access layers.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v24.2.dll

Declaration

C#

public interface IDataLayerAsync :
    IDataLayer,
    IDisposable,
    IDataLayerProvider,
    IXPDictionaryProvider

VB.NET

Public Interface IDataLayerAsync
    Inherits IDataLayer,
             IDisposable,
             IDataLayerProvider,
             IXPDictionaryProvider

Remarks

XPO provides the following IDataLayerAsync implementations:

• SimpleDataLayer - used by default.
• ThreadSafeDataLayer.

In a general, SimpleDataLayer is equal to ThreadSafeDataLayer, and the substitution of one component by another has no effect. However, you cannot use SimpleDataLayer or ThreadSafeDataLayer under the circumstances described below:

• SimpleDataLayer does not support concurrent access from multiple threads. Use ThreadSafeDataLayer in multi-threaded applications and web applications where you share a data access layer between multiple users. Use ThreadSafeDataLayer if you use Instant Feedback data sources.
• ThreadSafeDataLayer implies that you never add new classes to XPDictionary or modify XPO metadata at runtime. You should add all required classes to XPDictionary before you create ThreadSafeDataLayer. You cannot dynamically create new classes/properties or add attributes after you instantiate a ThreadSafeDataLayer object.
• ThreadSafeDataLayer does not support database level transactions.

Extension Methods

Query<T>()