TagPrefixAttribute Class


Defines the tag prefix used in a Web page to identify custom controls. This class cannot be inherited.

public ref class TagPrefixAttribute sealed : Attribute
[System.AttributeUsage(System.AttributeTargets.Assembly, AllowMultiple=true)]
public sealed class TagPrefixAttribute : Attribute
type TagPrefixAttribute = class
    inherit Attribute
Public NotInheritable Class TagPrefixAttribute
Inherits Attribute


using System;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

[assembly:TagPrefix("CustomControls", "custom")]

namespace CustomControls

    // Simple custom control
    public class MyCS_Control : Control
            private String message = "Hello";
            public virtual String Message
                        return message;
                        message = value;
            [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")] 
            protected override void Render( HtmlTextWriter writer)
            writer.Write("<span style='background-color:aqua; font:8pt tahoma, verdana;'> "
                        + this.Message + "<br>" + "C# version. The time on the server is " + System.DateTime.Now.ToLongTimeString()
                        + "</span>");

Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls

<assembly: TagPrefix("CustomControls", "custom")> _

Namespace CustomControls
   ' Simple custom control
   Public Class MyVB_Control 
   Inherits Control
      Private message As String = "Hello"
      Public  Property getMessage() As String
            Return message
         End Get
         Set (ByVal value As String)
            message = value
         End Set
      End Property
      <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
      Protected Overrides Sub Render(writer As HtmlTextWriter)
         writer.Write(("<span style='background-color:aqua; font:8pt tahoma, verdana;'> " + Me.getMessage + "<br>" + "VB version. The time on the server is " + System.DateTime.Now.ToLongTimeString() + "</span>"))
      End Sub
   End Class
End Namespace 'CustomControls 


The TagPrefixAttribute class defines an assembly-level attribute needed to specify tag prefix aliases for custom controls. This attribute is used by tools such as Microsoft Visual Studio to automatically generate a Register directive in the ASP.NET page where the custom controls are used.

This directive registers the tag prefix with a namespace. Moreover, it specifies the assembly where the custom control code implementation resides. With this directive in place, you can use custom controls in a Web page declaratively.

For more information about using attributes, see Attributes.


TagPrefixAttribute(String, String)

Initializes a new instance of the TagPrefixAttribute class.



Gets the namespace prefix for the specified control.


Gets the tag prefix for the specified control.


When implemented in a derived class, gets a unique identifier for this Attribute.

(Inherited from Attribute)



Returns a value that indicates whether this instance is equal to a specified object.

(Inherited from Attribute)

Returns the hash code for this instance.

(Inherited from Attribute)

Gets the Type of the current instance.

(Inherited from Object)

When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.

(Inherited from Attribute)

When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.

(Inherited from Attribute)

Creates a shallow copy of the current Object.

(Inherited from Object)

Returns a string that represents the current object.

(Inherited from Object)

Explicit Interface Implementations

_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

Maps a set of names to a corresponding set of dispatch identifiers.

(Inherited from Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

Retrieves the type information for an object, which can be used to get the type information for an interface.

(Inherited from Attribute)

Retrieves the number of type information interfaces that an object provides (either 0 or 1).

(Inherited from Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Provides access to properties and methods exposed by an object.

(Inherited from Attribute)

Applies to

See also