ObjectDataSourceDisposingEventArgs Class
Assembly: System.Web (in system.web.dll)
The ObjectDataSourceDisposingEventArgs class is used in the OnObjectDisposing method to provide access to the business object instance after any data operations that are using the ObjectDataSource control and business object are performed, but before the business object is destroyed. The business object is accessed using the ObjectInstance property. By adding a delegate to handle the ObjectDisposing event, you can access any publicly exposed members of the business object to perform any final work or clean up.
The OnObjectDisposing method is not called by the ObjectDataSource control, if the method that performs data operations is a static method. No business object instance is created when the method is static.
The ObjectDataSource control exposes many events that you can handle to work with the underlying business object at various times in its lifecycle. The following table lists the events and the associated EventArgs classes and event handler delegates.
| Event | EventArgs | EventHandler |
|---|---|---|
| Occurs immediately before the instance of the business object is created. | ||
| Occurs immediately after the instance of the business object is created. | ObjectDataSourceEventArgs | ObjectDataSourceObjectEventHandler |
| Occurs before the data is retrieved. | ||
| Inserting, Updating, and Deleting. Occur before an insert, update, or delete operation is performed. | ||
| Occurs after the data is retrieved. | ||
| Inserted, Updated, and Deleted. Occur after the insert, update, or delete operation is completed. | ObjectDataSourceStatusEventArgs | ObjectDataSourceStatusEventHandler |
| ObjectDisposing. Occurs before a business object is destroyed. | ObjectDataSourceDisposingEventArgs |
This section contains two code examples. The first code example demonstrates how to use an ObjectDataSource control with a business object and a GridView control to display information. The second code example provides the example middle-tier business object that the first code example uses.
The following code example demonstrates how to use an ObjectDataSource control with a business object and a GridView control to display information. You might work with a business object that is very expensive (in terms of time or resources) to create for every data operation that your Web page performs. One way to work with an expensive object might be to create an instance of it once, and then cache it for subsequent operations instead of creating and destroying it for every data operation. This example demonstrates this pattern. You can handle the ObjectCreating event to check the cache for an object first, and then create an instance, only if one is not already cached. Then, handle the ObjectDisposing event to cache the business object for future use, instead of destroying it. In this example, the CancelEventArgs.Cancel property of the ObjectDataSourceDisposingEventArgs object is set to true, to direct the ObjectDataSource to not call the Dispose method on the instance.
The following code example provides an example middle-tier business object that the preceding code example uses. The code example consists of a basic business object, defined by the EmployeeLogic class, which is a class that maintains state and encapsulates business logic. For a complete working example, you must compile this code as a library, and then use these classes from an ASP page.
- AspNetHostingPermission for operating in a hosted environment. Demand value: LinkDemand; Permission value: Minimal.
- AspNetHostingPermission for operating in a hosted environment. Demand value: InheritanceDemand; Permission value: Minimal.
System.EventArgs
System.ComponentModel.CancelEventArgs
System.Web.UI.WebControls.ObjectDataSourceDisposingEventArgs
Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.