Occurs before an update operation.
Assembly: System.Web (in System.Web.dll)
Handle the event to perform additional initialization operations that are specific to your application, to validate the values of parameters, or to change the parameter values before the SqlDataSource control performs the update operation. The connection to the underlying data source is not yet open when the event handler delegate is called. Therefore, you cannot directly cancel the Update database operation by calling the Cancel method on the DbCommand object that is exposed by the SqlDataSourceCommandEventArgs object. You can, however, cancel the database operation by setting the Cancel property of the SqlDataSourceCommandEventArgs to true.
For more information about handling events, see Consuming Events.
Values are inserted into parameters without validation, which is a potential security threat. Use the event to validate parameter values before executing the query. For more information, see Script Exploits Overview.
The following code example demonstrates how to display data that is retrieved from a Microsoft SQL Server database in a DropDownList control and update the record using a TextBox control. The example shows how you can use a DbTransaction object to add transaction context when using the SqlDataSource control to update data.