TemplateContainerAttribute Class
Definition
Important
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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.
public ref class TemplateContainerAttribute sealed : Attribute[System.AttributeUsage(System.AttributeTargets.Property)]
public sealed class TemplateContainerAttribute : Attribute[<System.AttributeUsage(System.AttributeTargets.Property)>]
type TemplateContainerAttribute = class
inherit AttributePublic NotInheritable Class TemplateContainerAttribute
Inherits Attribute- Inheritance
- Attributes
Examples
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.
using System;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Collections;
namespace Samples.AspNet.CS.Controls
{
[ParseChildren(true)]
public class TemplatedFirstControl : Control, INamingContainer
{
private ITemplate firstTemplate;
private String text = null;
private Control myTemplateContainer;
[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")]
protected override void OnDataBinding(EventArgs e)
{
EnsureChildControls();
base.OnDataBinding(e);
}
[TemplateContainer(typeof(FirstTemplateContainer))]
public ITemplate FirstTemplate
{
get
{
return firstTemplate;
}
set
{
firstTemplate = value;
}
}
public String Text
{
get
{
return text;
}
set
{
text = value;
}
}
public String DateTime
{
get
{
return System.DateTime.Now.ToLongTimeString();
}
}
public Control MyTemplateContainer
{
get
{
return myTemplateContainer;
}
}
[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")]
protected override void CreateChildControls()
{
if (FirstTemplate != null)
{
myTemplateContainer = new FirstTemplateContainer(this);
FirstTemplate.InstantiateIn(myTemplateContainer);
Controls.Add(myTemplateContainer);
}
else
{
Controls.Add(new LiteralControl(Text + " " + DateTime));
}
}
}
public class FirstTemplateContainer : Control, INamingContainer
{
private TemplatedFirstControl parent;
public FirstTemplateContainer(TemplatedFirstControl parent)
{
this.parent = parent;
}
public String Text
{
get
{
return parent.Text;
}
}
public String DateTime
{
get
{
return parent.DateTime;
}
}
}
}
' File name:templatecontainerattribute.vb.
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
End Class
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
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
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="C#" %>
<%@ Import Namespace="System.Reflection" %>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS.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 void Page_Load(object sender, EventArgs e)
{
// <Snippet3>
// Get the class type for which to access metadata.
Type clsType = typeof(TemplatedFirstControl);
// Get the PropertyInfo object for FirstTemplate.
PropertyInfo pInfo = clsType.GetProperty("FirstTemplate");
// See if the TemplateContainer attribute is defined for this property.
bool isDef = Attribute.IsDefined(pInfo, typeof(TemplateContainerAttribute));
// Display the result if the attribute exists.
if (isDef)
{
TemplateContainerAttribute tca =
(TemplateContainerAttribute)Attribute.GetCustomAttribute(pInfo, typeof(TemplateContainerAttribute));
Response.Write("The binding direction is: " + tca.BindingDirection.ToString());
}
// </Snippet3>
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>TemplateContainerAttribute Example</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<aspSample:TemplatedFirstControl id="TemplatedFirstControl1" runat="server">
<FirstTemplate>This is the first template.</FirstTemplate>
</aspSample:TemplatedFirstControl>
<br />
<aspSample:TemplatedFirstControl id="TemplatedFirstControl2" runat="server">
</aspSample:TemplatedFirstControl>
</div>
</form>
</body>
</html>
<%@ 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)
' <Snippet3>
' 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
' </Snippet3>
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<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>
Remarks
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 Attributes.
Constructors
| TemplateContainerAttribute(Type) |
Initializes a new instance of the TemplateContainerAttribute class using the specified container type. |
| TemplateContainerAttribute(Type, BindingDirection) |
Initializes a new instance of the TemplateContainerAttribute class using the specified container type and the BindingDirection property. |
Properties
| BindingDirection |
Gets the binding direction of the container control. |
| ContainerType |
Gets the container control type. |
| TypeId |
When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute) |
Methods
| Equals(Object) |
Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute) |
| GetHashCode() |
Returns the hash code for this instance. (Inherited from Attribute) |
| GetType() |
Gets the Type of the current instance. (Inherited from Object) |
| IsDefaultAttribute() |
When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute) |
| Match(Object) |
When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute) |
| MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
| ToString() |
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) |
| _Attribute.GetTypeInfoCount(UInt32) |
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) |
