Gets or sets a value indicating whether the ObjectDataSource control has data caching enabled.
Assembly: System.Web (in System.Web.dll)
The ObjectDataSource control supports data caching. While data is cached, calls to the Select method retrieve data from the cache rather than the ObjectDataSource creating an instance of the business object and calling its data method. When the cache expires, the Select method retrieves data from the business object, and then caches the data again.
The ObjectDataSource control automatically caches data when the property is set to true and the CacheDuration property is set to a value greater than 0, which indicates the number of seconds that the cache stores data before the cache entry is discarded. A value of 0 indicates an infinitely long cache.
The following three examples show a Web page, a code-behind page class, and a data-access class that retrieve records from the Employees table in the Northwind database.
The first example shows a Web page that contains two ObjectDataSource controls, a DropDownList control, and a DetailsView control. The first ObjectDataSource control and the DropDownList control are used to retrieve and display employee names from the database. The second ObjectDataSource control and the DetailsView control are used to retrieve and display the employee record that is selected by the user.
Caching is enabled for the ObjectDataSource control. Therefore, each record is retrieved only one time from the database. The CacheKeyDependency property is set to "EmployeeDetails", but any string value can work as the key. The Web page also includes a Button control that the user can click to expire the cached data.
The second example shows a handler for the Load event and a handler for the Click event of the Button control. The Load event handler creates a cache item with a key set to the CacheKeyDependency value. The Click event handler removes the cache item whose key is equal to the CacheKeyDependency value. When the cache item is removed, all the cached data that is dependent on the key is expired.
The third example shows the data access class that interacts with the Northwind database. The class uses LINQ to query the Employees table. The example requires a LINQ to SQL class that represents the Northwind database and the Employees table. For more information, see How to: Create LINQ to SQL Classes in a Web Project.
Available since 2.0