TemplateContainerAttribute 类

参考

定义

命名空间:: System.Web.UI

程序集:: System.Web.dll

重要

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声明属性的容器控件的基类型，该属性返回 ITemplate 接口并用 TemplateContainerAttribute 特性进行标记。具有 ITemplate 属性的控件必须实现 INamingContainer 接口。此类不能被继承。

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

继承: Object

Attribute
TemplateContainerAttribute

属性: AttributeUsageAttribute

示例

下面的代码示例演示如何创建命名 TemplatedFirstControl 的模板化控件并将其与名为 FirstTemplateContainer的容器相关联。这样，就可以创建自定义控件，这些控件在未指定模板时显示服务器时间，并在指定模板时显示模板的内容。

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

以下 Web 窗体演示如何使用在前面的代码示例中创建的自定义控件。页面上放置了 TemplatedFirstControl 两个实例：

第一个实例包括模板 <FirstTemplate>。
第二个实例不包括 <FirstTemplate>;因此，它只显示时间。

<%@ 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>

注解

Type作为对象参数TemplateContainerAttribute传入的对象由分析器用作数据绑定表达式中使用的对象类型Container。其属性返回 ITemplate 接口且标记有接口的 TemplateContainerAttribute控件必须实现 INamingContainer 该接口。

有关使用属性的详细信息，请参阅 “属性”。

构造函数

TemplateContainerAttribute(Type)	使用指定的容器类型初始化 TemplateContainerAttribute 类的新实例。
TemplateContainerAttribute(Type, BindingDirection)	使用指定的容器类型和 BindingDirection 属性初始化 TemplateContainerAttribute 类的新实例。

属性

BindingDirection	获取容器控件的绑定方向。
ContainerType	获取容器控件类型。
TypeId	在派生类中实现时，获取此 Attribute 的唯一标识符。 (继承自 Attribute)

方法

Equals(Object)	返回一个值，该值指示此实例是否与指定的对象相等。 (继承自 Attribute)
GetHashCode()	返回此实例的哈希代码。 (继承自 Attribute)
GetType()	获取当前实例的 Type。 (继承自 Object)
IsDefaultAttribute()	在派生类中重写时，指示此实例的值是否是派生类的默认值。 (继承自 Attribute)
Match(Object)	当在派生类中重写时，返回一个指示此实例是否等于指定对象的值。 (继承自 Attribute)
MemberwiseClone()	创建当前 Object 的浅表副本。 (继承自 Object)
ToString()	返回表示当前对象的字符串。 (继承自 Object)

显式接口实现

_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)	将一组名称映射为对应的一组调度标识符。 (继承自 Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)	检索对象的类型信息，然后可以使用该信息获取接口的类型信息。 (继承自 Attribute)
_Attribute.GetTypeInfoCount(UInt32)	检索对象提供的类型信息接口的数量（0 或 1）。 (继承自 Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)	提供对某一对象公开的属性和方法的访问。 (继承自 Attribute)

适用于

TemplateContainerAttribute 类

定义

示例

注解

构造函数

属性

方法

显式接口实现

适用于

另请参阅

其他资源