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Page.MasterPageFile Property

Updated: May 2011

Gets or sets the virtual path of the master page.

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

public virtual string MasterPageFile { get; set; }
<asp:Page MasterPageFile="String" />

Property Value

Type: System.String
The virtual path of the master page.


The MasterPageFile property is set after the PreInit event is complete.


The file specified in the MasterPageFile property does not exist.

- or -

The page does not have a Content control as the top level control.

The MasterPageFile property is a virtual path (from the root of the application) of the master page file that is associated with this page. The MasterPageFile property can be set only in the PreInit event; attempting to set the MasterPageFile property after the PreInit event will throw an InvalidOperationException exception. If the MasterPageFile property is not valid, an exception of type HttpException is thrown later in the page life cycle, but no exception is thrown when the property is set in the PreInit event.

Pages that have the MasterPageFile property set are content pages, and therefore can contain only top-level controls that are Content controls.

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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




May 2011

Clarified that this is a virtual path, not a file name.

Customer feedback.