This documentation is archived and is not being maintained.

Page.EnableViewStateMac Property

Updated: May 2010

Gets or sets a value indicating whether ASP.NET should verify message authentication codes (MAC) in the page's view state when the page is posted back from the client.

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

public function get EnableViewStateMac () : boolean 
public function set EnableViewStateMac (value : boolean)
<asp:Page EnableViewStateMac="True|False" />

Property Value

Type: System.Boolean
true if the view state should be MAC checked and encoded; otherwise, false. The default is true.

A view-state MAC is an encrypted version of the hidden variable that a page's view state is persisted to when the page is sent to the browser. When this property is set to true, the encrypted view state is checked to verify that it has not been tampered with on the client.

Do not set this property in code. Set the EnableViewStateMac attribute using the @ Page directive in the .aspx file. When the page is requested, the dynamically generated class sets the property.

Security noteSecurity Note:

This attribute should never be set to false in a production Web site, even if the application or page does not use view state. The view-state MAC helps ensure the security of other ASP.NET functions in addition to view state.

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, 1.1, 1.0




May 2010

Corrected text to indicate that the default is true and added a warning against setting the property value to false in a production Web site.

Content bug fix.