Declares the base type of the container control of a property that returns an ITemplate interface and is marked with the TemplateContainerAttribute attribute. The control with the ITemplate property must implement the INamingContainer interface. This class cannot be inherited.
(in System.Web.dll)
'Usage
Dim instance As TemplateContainerAttribute
'Declaration
<AttributeUsageAttribute(AttributeTargets.Property)> _
<AspNetHostingPermissionAttribute(SecurityAction.LinkDemand, Level := AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class TemplateContainerAttribute _
Inherits Attribute
The Type object that is passed in as a parameter of the TemplateContainerAttribute object is used by the parser as the type of Container object that is used in data-binding expressions. The control whose property returns an ITemplate interface and is marked with the TemplateContainerAttribute, must implement the INamingContainer interface.
For more information about using attributes, see Extending Metadata Using Attributes.
The following code example demonstrates how to create a templated control named TemplatedFirstControl and associate it with a container named FirstTemplateContainer. This allows the creation of custom controls that display the server time when the template is not specified and the template's content when the template is specified.
' File name:templatecontainerattribute.vb.
Imports System
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Collections
Namespace Samples.AspNet.VB.Controls
<ParseChildren(True)> _
Public Class VB_TemplatedFirstControl
Inherits Control
Implements INamingContainer
Private _firstTemplate As ITemplate
Private [_text] As [String] = Nothing
Private _myTemplateContainer As Control
<System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
Protected Overrides Sub OnDataBinding(ByVal e As EventArgs)
EnsureChildControls()
MyBase.OnDataBinding(e)
End Sub
Public Property FirstTemplate() As ITemplate
Get
Return _firstTemplate
End Get
Set(ByVal value As ITemplate)
_firstTemplate = Value
End Set
End Property
Public Property [Text]() As [String]
Get
Return [_text]
End Get
Set(ByVal value As [String])
[_text] = Value
End Set
End Property
Public ReadOnly Property DateTime() As [String]
Get
Return System.DateTime.Now.ToLongTimeString()
End Get
End Property
Public ReadOnly Property MyTemplateContainer() As Control
Get
Return _myTemplateContainer
End Get
End Property
<System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
Protected Overrides Sub CreateChildControls()
If Not (FirstTemplate Is Nothing) Then
_myTemplateContainer = New VB_FirstTemplateContainer(Me)
FirstTemplate.InstantiateIn(_myTemplateContainer)
Controls.Add(_myTemplateContainer)
Else
Controls.Add(New LiteralControl([Text] + " " + DateTime))
End If
End Sub 'CreateChildControls
End Class 'VB_TemplatedFirstControl
Public Class VB_FirstTemplateContainer
Inherits Control
Implements INamingContainer
Private _parent As VB_TemplatedFirstControl
Public Sub New(ByVal parent As VB_TemplatedFirstControl)
Me._parent = parent
End Sub 'New
Public ReadOnly Property [Text]() As [String]
Get
Return _parent.Text
End Get
End Property
Public ReadOnly Property DateTime() As [String]
Get
Return _parent.DateTime
End Get
End Property
End Class 'VB_FirstTemplateContainer
End Namespace 'CustomControls
The following Web form demonstrates how to use the custom control created in the preceding code example. Two instances of the TemplatedFirstControl are placed on the page:
The first instance includes the template <FirstTemplate>.
The second instance does not include <FirstTemplate>; therefore, it shows just the time.
<%@ Page Language="VB" %>
<%@ Import Namespace="System.Reflection" %>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB.Controls" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
' Get the class type for which to access metadata.
Dim clsType As Type = GetType(VB_TemplatedFirstControl)
' Get the PropertyInfo object for FirstTemplate.
Dim pInfo As PropertyInfo = clsType.GetProperty("FirstTemplate")
' See if the TemplateContainer attribute is defined for this property.
Dim isDef As Boolean = Attribute.IsDefined(pInfo, GetType(TemplateContainerAttribute))
' Display the result if the attribute exists.
If isDef Then
Dim tca As TemplateContainerAttribute = CType(Attribute.GetCustomAttribute(pInfo, GetType(TemplateContainerAttribute)), TemplateContainerAttribute)
Response.Write("The binding direction is: " & tca.BindingDirection.ToString())
End If
End Sub
</script>
<html >
<head runat="server">
<title>TemplateContainerAttribute Example</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<aspSample:VB_TemplatedFirstControl id="TemplatedFirstControl1" runat="server">
<FirstTemplate>This is the first template.</FirstTemplate>
</aspSample:VB_TemplatedFirstControl>
<br />
<aspSample:VB_TemplatedFirstControl id="TemplatedFirstControl2" runat="server">
</aspSample:VB_TemplatedFirstControl>
</div>
</form>
</body>
</html>
System..::.Attribute
System.Web.UI..::.TemplateContainerAttribute
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, 1.1, 1.0
Reference
Other Resources