SupportsEventValidationAttribute Class
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SupportsEventValidationAttribute Class

Defines the metadata attribute that Web server controls use to indicate support for event validation. This class cannot be inherited.

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

[AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple = false)]
[AspNetHostingPermissionAttribute(SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
public sealed class SupportsEventValidationAttribute : Attribute

Event validation prevents forged postbacks to an ASP.NET Web page and can be enabled through the EnableEventValidation page directive.

For more information, see EnableEventValidation. For more information about attributes, see Extending Metadata Using Attributes.

Notes to Implementers:

If you do not define the SupportsEventValidationAttribute attribute, your custom control does not automatically participate in event validation. However, your control can explicitly call ValidateEvent. If you handle event registration and validation, call ValidateEvent, and then you do not need to define this attribute on the control.


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0

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