Gets or sets a value that specifies whether event validation is enabled.
Assembly: System.Web (in System.Web.dll)
The attribute indicates whether event validation should be performed. The default value is true. A Web application can optionally disable event validation to revert to .NET Framework version 1.0 behavior.
The base control checks this attribute to determine whether it should validate events. A derived control does not inherit this base control attribute, and so it is exempt from event validation by default. You still instruct ASP.NET to perform event validation on the derived control by adding the attribute to the derived control itself and setting it to true.
Event validation reduces the risk of unauthorized postback requests and callbacks. It instructs ASP.NET to validate only those events that can be raised in the control during a postback request or callback. With this model, a control registers its events during rendering and then validates the events during the post-back or callback handling. All event-driven controls in ASP.NET use this feature by default.