.NET Framework Class Library
PersistChildrenAttribute Class

Defines an attribute that is used by ASP.NET server controls to indicate at design time whether nested content that is contained within a server control corresponds to controls or to properties of the server control. This class cannot be inherited.

Inheritance Hierarchy
SystemObject
   SystemAttribute
    System.Web.UIPersistChildrenAttribute

Namespace:   System.Web.UI
Assembly:  System.Web (in System.Web.dll)
Syntax
<[%$TOPIC/xdad9hb8_en-us_VS_110_2_0_0_0_0%]([%$TOPIC/xdad9hb8_en-us_VS_110_2_0_0_0_1%].Class)> _
Public NotInheritable Class PersistChildrenAttribute _
	Inherits [%$TOPIC/xdad9hb8_en-us_VS_110_2_0_0_0_2%]
[[%$TOPIC/xdad9hb8_en-us_VS_110_2_0_1_0_0%]([%$TOPIC/xdad9hb8_en-us_VS_110_2_0_1_0_1%].Class)]
public sealed class PersistChildrenAttribute : [%$TOPIC/xdad9hb8_en-us_VS_110_2_0_1_0_2%]
[[%$TOPIC/xdad9hb8_en-us_VS_110_2_0_2_0_0%]([%$TOPIC/xdad9hb8_en-us_VS_110_2_0_2_0_1%]::Class)]
public ref class PersistChildrenAttribute sealed : public [%$TOPIC/xdad9hb8_en-us_VS_110_2_0_2_0_2%]
[<[%$TOPIC/xdad9hb8_en-us_VS_110_2_0_3_0_0%]>]
[<[%$TOPIC/xdad9hb8_en-us_VS_110_2_0_3_0_1%]([%$TOPIC/xdad9hb8_en-us_VS_110_2_0_3_0_2%].Class)>]
type PersistChildrenAttribute =  
    class 
        inherit [%$TOPIC/xdad9hb8_en-us_VS_110_2_0_3_0_3%] 
    end

The PersistChildrenAttribute type exposes the following members.

Constructors
  NameDescription
Public method PersistChildrenAttribute(Boolean)Initializes a new instance of the PersistChildrenAttribute class using a Boolean value indicating whether to persist nested content as nested controls.
Public method PersistChildrenAttribute(Boolean, Boolean)Initializes a new instance of the PersistChildrenAttribute class using two Boolean values. One indicating whether to persist nested content as nested controls and the other indicating whether to use a custom persistence method.
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Properties
  NameDescription
Public property PersistGets a value that indicates whether the nested content is persisted as nested controls at design time.
Public property TypeIdWhen implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.)
Public property UsesCustomPersistenceGets a value indicating whether the server control provides custom persistence of nested controls at design time.
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Methods
  NameDescription
Public method EqualsDetermines whether the specified object is equal to the current object. (Overrides AttributeEquals(Object).)
Public method GetHashCodeServes as a hash function for the PersistChildrenAttribute class. (Overrides AttributeGetHashCode.)
Public method GetTypeGets the Type of the current instance. (Inherited from Object.)
Public method IsDefaultAttributeReturns a value indicating whether the value of the current instance of the PersistChildrenAttribute class is the default value of the derived clss. (Overrides AttributeIsDefaultAttribute.)
Public method MatchWhen overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)
Public method ToStringReturns a string that represents the current object. (Inherited from Object.)
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Fields
  NameDescription
Public field Static member DefaultIndicates the default attribute state. The Default field is read-only.
Public field Static member NoIndicates that nested content should not persist as nested controls at design time. This field is read-only.
Public field Static member YesIndicates that nested content should persist as controls at design time. The Yes field is read-only.
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Explicit Interface Implementations
  NameDescription
Explicit interface implemetation Private method _AttributeGetIDsOfNamesMaps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute.)
Explicit interface implemetation Private method _AttributeGetTypeInfoRetrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute.)
Explicit interface implemetation Private method _AttributeGetTypeInfoCountRetrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute.)
Explicit interface implemetation Private method _AttributeInvokeProvides access to properties and methods exposed by an object. (Inherited from Attribute.)
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Remarks

The PersistChildrenAttribute is used in combination with the ParseChildrenAttribute to determine how nested content of a control is interpreted. If PersistChildrenAttribute is true and ParseChildrenAttribute is false, the nested content contained within an ASP.NET server control is persisted as controls. If PersistChildrenAttribute is false and ParseChildrenAttribute is true, the nested content is persisted as properties of the server control. For more information about using attributes, see Extending Metadata Using Attributes.

Examples

The code example in this section contains two parts. The first code example demonstrates how to set the metadata of a custom control so that at design time, its nested content is persisted as properties of the control. The second code example demonstrates how to use classes in an ASP.NET page.

The following code example demonstrates how to apply the PersistChildrenAttribute attribute so that none of a custom server control's nested controls are persisted as nested controls. The custom server control named CollectionPropertyControl has the PersistChildrenAttribute attribute set to false so that the Employee objects that are added are persisted as nested elements.

' Create a namespace that defines two classes, one a custom control, Employee, 
' which is created for every instance of a child element with its name 
' declared in a page associated with this namespace, the other, Employees, 
' which contains these child elements. 
Imports System
Imports System.Collections
Imports System.Drawing
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Security.Permissions

Namespace PersistChildrenSampleVB

' Create a class that will be rendered as a child of the control 
' that has the ParseChildren attribute applied to it.
 <AspNetHostingPermission(SecurityAction.Demand, _
   Level:=AspNetHostingPermissionLevel.Minimal)> _
 Public NotInheritable Class Employee
   Private _name As String 
   Private _title As String 
   Private _alias As String 


   Public Sub New()
      Me.New("", "", "")
   End Sub 'New 


   Public Sub New(name As String, title As String, employeeAlias As String)
      Me._name = name
      Me._title = title
      Me._alias = employeeAlias
   End Sub 'New 

   Public Property Name() As String 
      Get 
         Return _name
      End Get 
      Set
         _name = value
      End Set 
   End Property 


   Public Property Title() As String 
      Get 
         Return _title
      End Get 
      Set
         _title = value
      End Set 
   End Property 


   Public Property [Alias]() As String 
      Get 
         Return _alias
      End Get 
      Set
         _alias = value
      End Set 
   End Property 
End Class 'Employee

 ' Use the PersistChildren attribute to set the Persist 
 ' property to false so that none of this class's 
 ' child controls will be persisted as controls. They will 
 ' be persisted only as child elements of this class. 
 ' If you set the PersistChildren attribute to true, or if you 
 ' do not include this attribute when you create a control, 
 ' the child controls will be persisted as controls.
 <PersistChildren(False)>  _
 <AspNetHostingPermission(SecurityAction.Demand, _
   Level:=AspNetHostingPermissionLevel.Minimal)> _
 Public NotInheritable Class CollectionPropertyControl
   Inherits Control
   Private _header As String 
   Private _employees As New ArrayList()


   Public Property Header() As String 
      Get 
         Return _header
      End Get 
      Set
         _header = value
      End Set 
   End Property 




   Public ReadOnly Property Employees() As ArrayList
      Get 
         Return _employees
      End Get 
   End Property 

   ' Override the CreateChildControls method to  
   ' add child controls to the Employees property when this 
   ' custom control is requested from a page. 
   Protected Overrides Sub CreateChildControls()
      Dim label As New Label()
      label.Text = Header
      label.BackColor = Color.Beige
      label.ForeColor = Color.Red
      Controls.Add(label)
      Controls.Add(New LiteralControl("<BR> <BR>"))

      Dim table As New Table()
      Dim htr As New TableRow()

      Dim hcell1 As New TableHeaderCell()
      hcell1.Text = "Name"
      htr.Cells.Add(hcell1)

      Dim hcell2 As New TableHeaderCell()
      hcell2.Text = "Title"
      htr.Cells.Add(hcell2)

      Dim hcell3 As New TableHeaderCell()
      hcell3.Text = "Alias"
      htr.Cells.Add(hcell3)
      table.Rows.Add(htr)

      table.BorderWidth = Unit.Pixel(2)
      table.BackColor = Color.Beige
      table.ForeColor = Color.Red
      Dim employee As Employee
      For Each employee In  Employees
         Dim tr As New TableRow()

         Dim cell1 As New TableCell()
         cell1.Text = employee.Name
         tr.Cells.Add(cell1)

         Dim cell2 As New TableCell()
         cell2.Text = employee.Title
         tr.Cells.Add(cell2)

         Dim cell3 As New TableCell()
         cell3.Text = employee.Alias
         tr.Cells.Add(cell3)

         table.Rows.Add(tr)
      Next employee
      Controls.Add(table)
   End Sub 'CreateChildControls 
 End Class 'CollectionPropertyControl
End Namespace ' PersistChildrenSampleVB
using System;
using System.Collections;
using System.Drawing;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Security.Permissions;

namespace PersistChildrenSamples
{
   // The child element class.
   [AspNetHostingPermission(SecurityAction.Demand, 
      Level=AspNetHostingPermissionLevel.Minimal)]
   public sealed class Employee
   {
      private String name;
      private String title;
      private String alias;

      public Employee():this ("","",""){}

      public Employee (String name, String title, String alias)
      {
         this.name = name;
         this.title = title;
         this.alias = alias;
      }
      public String Name
      {
         get
         {
            return name;
         }
         set
         {
            name = value;
         }
      }

      public String Title
      {
         get
         {
            return title;
         }
         set
         {
            title = value;
         }
      }

      public String Alias
      {
         get
         {
            return alias;
         }
         set
         {
            alias = value;
         }
      }
   }
   // Use the PersistChildren attribute to set the Persist 
   // property to false so that none of this class's 
   // child controls will be persisted as controls. They will 
   // be persisted only as child elements of this class. 
   // If you set the PersistChildren attribute to true, or if you 
   // do not include this attribute when you create a control, 
   // the child controls will be persisted as controls.   
   [PersistChildren(false)]
   [AspNetHostingPermission(SecurityAction.Demand, 
      Level=AspNetHostingPermissionLevel.Minimal)]
   public sealed class CollectionPropertyControl : Control
   {  
      private String header;
      private ArrayList employees = new ArrayList();

      public String Header
      {
         get
         {
            return header;
         }
         set
         {
            header = value;
         }
      }



      public ArrayList Employees
      {
         get 
         {
            return employees;
         }
      }
      // Override the CreateChildControls method to  
      // add child controls to the Employees property when this 
      // custom control is requested from a page. 
      protected override void CreateChildControls()
      {
         Label label = new Label();
         label.Text = Header;
         label.BackColor = Color.Beige;
         label.ForeColor = Color.Red;
         Controls.Add(label);
         Controls.Add(new LiteralControl("<BR> <BR>"));

         Table table = new Table();
         TableRow htr = new TableRow();

         TableHeaderCell hcell1 = new TableHeaderCell();    
         hcell1.Text = "Name";
         htr.Cells.Add(hcell1);

         TableHeaderCell hcell2 = new TableHeaderCell();
         hcell2.Text = "Title";
         htr.Cells.Add(hcell2);

         TableHeaderCell hcell3 = new TableHeaderCell();
         hcell3.Text = "Alias";
         htr.Cells.Add(hcell3);
         table.Rows.Add(htr);

         table.BorderWidth = 2;
         table.BackColor = Color.Beige;
         table.ForeColor = Color.Red;
         foreach (Employee employee in Employees)
         {
            TableRow tr = new TableRow();

            TableCell cell1 = new TableCell();
            cell1.Text = employee.Name;
            tr.Cells.Add(cell1);

            TableCell cell2 = new TableCell();
            cell2.Text = employee.Title;
            tr.Cells.Add(cell2);

            TableCell cell3 = new TableCell();
            cell3.Text = employee.Alias;
            tr.Cells.Add(cell3);

            table.Rows.Add(tr);
         }
         Controls.Add(table);

      }
   }
}

The following code example demonstrates how to use the CollectionPropertyControl and Employee classes in an ASP.NET page.

<%@ Page Language="VB" %>
<%@ Register TagPrefix="AspSample" Assembly="Samples.AspNet.VB.Controls" Namespace="PersistChildrenSampleVB" %>


<!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)

    ' Create two new employees and add them to the custom control.
    Dim e1 As New Employee("Employee 1", "Title 1", "Alias 1")
    Dim e2 As New Employee("Employee 2", "Title 2", "Alias 2")
    CollectionPropertyControl1.Employees.Add(e1)
    CollectionPropertyControl1.Employees.Add(e2)

    ' Verify attribute values.
    Dim p As PersistChildrenAttribute = _
    Attribute.GetCustomAttribute(GetType(CollectionPropertyControl), _
    GetType(PersistChildrenAttribute))

    Dim sb As New StringBuilder()
    sb.Append("The Persist property is " & p.Persist.ToString() & "<br />")
    sb.Append("The UseCustomPersistence property is " & p.UsesCustomPersistence.ToString() & "<br />")
    sb.Append("The IsDefault method returns " & p.IsDefaultAttribute().ToString())
    Message.Text = sb.ToString()

  End Sub

</script>


<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>PersistChildrenAttribute</title>
</head>
<body>
    <form id="Form1" runat="server">
    <div>
      <asp:Label ID="Message"
                 runat="server"/>
      <AspSample:CollectionPropertyControl id="CollectionPropertyControl1" 
                                           runat="server">
      </AspSample:CollectionPropertyControl>
    </div>
    </form>
</body>
</html>
<%@ Page Language="C#" %>
<%@ Register TagPrefix="AspSample" Assembly="Samples.AspNet.CS.Controls" Namespace="PersistChildrenSamples" %>

<!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)
  {

    // Create two new employees and add them to the custom control.
    Employee e1 = new Employee("Employee 1", "Title 1", "Alias 1");
    Employee e2 = new Employee("Employee 2", "Title 2", "Alias 2");
    CollectionPropertyControl1.Employees.Add(e1);
    CollectionPropertyControl1.Employees.Add(e2);

    // Verify attribute values.
    PersistChildrenAttribute p =
      (PersistChildrenAttribute)Attribute.GetCustomAttribute(typeof(CollectionPropertyControl), 
      typeof(PersistChildrenAttribute));

    StringBuilder sb = new StringBuilder();
    sb.Append("The Persist property is " + p.Persist.ToString() + "<br />");
    sb.Append("The UseCustomPersistence property is " + p.UsesCustomPersistence.ToString() + "<br />");
    sb.Append("The IsDefault method returns " + p.IsDefaultAttribute().ToString());
    Message.Text = sb.ToString();

  }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>PersistChildrenAttribute</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
      <asp:Label ID="Message"
                 runat="server"/>
      <AspSample:CollectionPropertyControl id="CollectionPropertyControl1" 
                                           runat="server">
      </AspSample:CollectionPropertyControl>
    </div>
    </form>
</body>
</html>
Version Information

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0
Platforms

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.