TemplateContainerAttribute Klass

Definition

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 Attribute

Public NotInheritable Class TemplateContainerAttribute
Inherits Attribute

Arv

Object

Attribute

TemplateContainerAttribute

Attribut

AttributeUsageAttribute

Exempel

I följande kodexempel visas hur du skapar en mallkontroll med namnet TemplatedFirstControl och associerar den med en container med namnet FirstTemplateContainer. På så sätt kan du skapa anpassade kontroller som visar servertiden när mallen inte har angetts och mallens innehåll när mallen har angetts.

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

Följande webbformulär visar hur du använder den anpassade kontroll som skapades i föregående kodexempel. Två instanser av TemplatedFirstControl placeras på sidan:

• Den första instansen innehåller mallen <FirstTemplate>.

• Den andra instansen innehåller <FirstTemplate>inte . Därför visas bara tiden.

<%@ 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>

Kommentarer

Objektet Type som skickas som en parameter TemplateContainerAttribute för objektet används av parsern som den typ av Container objekt som används i databindningsuttryck. Kontrollen vars egenskap returnerar ett ITemplate gränssnitt och är markerad med TemplateContainerAttributemåste implementera INamingContainer gränssnittet.

Mer information om hur du använder attribut finns i Attribut.

Se även

• Attribute
• Utöka metadata med hjälp av attribut