EnableEventValidation Property
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Page.EnableEventValidation Property


Gets or sets a value indicating whether the page validates postback and callback events.

Namespace:   System.Web.UI
Assembly:  System.Web (in System.Web.dll)

public virtual bool EnableEventValidation { get; set; }

Property Value

Type: System.Boolean

true if the page validates postback and callback events; otherwise, false.The default is true.

Exception Condition

The EnableEventValidation property was set after the page was initialized.

When the EnableEventValidation property is set to true, ASP.NET validates that a control event originated from the user interface that was rendered by that control. A control registers its events during rendering and then validates the events during postback or callback handling. For example, if a list control includes options numbered 1, 2, or 3 when the page is rendered, and if a postback request is received specifying option number 4, ASP.NET raises an exception. All event-driven controls in ASP.NET use this feature by default.

If you write client script that changes a control in the client at run time, you might have to use the RegisterForEventValidation method in order to avoid false event validation errors.

System_CAPS_security Security Note

This feature reduces the risk of unauthorized or malicious postback requests and callbacks. It is strongly recommended that you do not disable event validation.

You set the EnableEventValidation property by setting the enableEventValidation attribute of the directive or the enableEventValidation attribute of the element in the Web.config file. If you set this property in code, you must set it before the page is initialized.

.NET Framework
Available since 2.0
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