Defines a metadata attribute that you can use when developing ASP.NET server controls. Use the ParseChildrenAttribute class to indicate how the page parser should treat content nested inside a server control tag declared on a page. This class cannot be inherited.
Assembly: System.Web (in System.Web.dll)
<[%$TOPIC/ytc87195_en-us_VS_110_2_0_0_0_0%]([%$TOPIC/ytc87195_en-us_VS_110_2_0_0_0_1%].Class)> _
Public NotInheritable Class ParseChildrenAttribute _
Inherits [%$TOPIC/ytc87195_en-us_VS_110_2_0_0_0_2%]
[[%$TOPIC/ytc87195_en-us_VS_110_2_0_1_0_0%]([%$TOPIC/ytc87195_en-us_VS_110_2_0_1_0_1%].Class)]
public sealed class ParseChildrenAttribute : [%$TOPIC/ytc87195_en-us_VS_110_2_0_1_0_2%]
[[%$TOPIC/ytc87195_en-us_VS_110_2_0_2_0_0%]([%$TOPIC/ytc87195_en-us_VS_110_2_0_2_0_1%]::Class)]
public ref class ParseChildrenAttribute sealed : public [%$TOPIC/ytc87195_en-us_VS_110_2_0_2_0_2%]
[<[%$TOPIC/ytc87195_en-us_VS_110_2_0_3_0_0%]>]
[<[%$TOPIC/ytc87195_en-us_VS_110_2_0_3_0_1%]([%$TOPIC/ytc87195_en-us_VS_110_2_0_3_0_2%].Class)>]
type ParseChildrenAttribute =
class
inherit [%$TOPIC/ytc87195_en-us_VS_110_2_0_3_0_3%]
end
The ParseChildrenAttribute type exposes the following members.
| Name | Description | |
|---|---|---|
![]() | ParseChildrenAttribute | Initializes a new instance of the ParseChildrenAttribute class. |
![]() | ParseChildrenAttribute(Boolean) | Initializes a new instance of the ParseChildrenAttribute class using the ChildrenAsProperties property to determine if the elements that are contained within a server control are parsed as properties of the server control. |
![]() | ParseChildrenAttribute(Type) | Initializes a new instance of the ParseChildrenAttribute class using the ChildControlType property to determine which elements that are contained within a server control are parsed as controls. |
![]() | ParseChildrenAttribute(Boolean, String) | Initializes a new instance of the ParseChildrenAttribute class using the childrenAsProperties and defaultProperty parameters. |
| Name | Description | |
|---|---|---|
![]() | ChildControlType | Gets a value indicating the allowed type of a control. |
![]() | ChildrenAsProperties | Gets or sets a value indicating whether to parse the elements that are contained within a server control as properties. |
![]() | DefaultProperty | Gets or sets the default property for the server control into which the elements are parsed. |
![]() | TypeId | When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.) |
| Name | Description | |
|---|---|---|
![]() | Equals | Determines whether the specified object is equal to the current object. (Overrides AttributeEquals(Object).) |
![]() | GetHashCode | Serves as a hash function for the ParseChildrenAttribute object. (Overrides AttributeGetHashCode.) |
![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() | IsDefaultAttribute | Returns a value indicating whether the value of the current instance of the ParseChildrenAttribute class is the default value of the derived class. (Overrides AttributeIsDefaultAttribute.) |
![]() | Match | When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.) |
![]() | ToString | Returns a string that represents the current object. (Inherited from Object.) |
| Name | Description | |
|---|---|---|
![]() | Default | Defines the default value for the ParseChildrenAttribute class. This field is read-only. |
![]() | ParseAsChildren | Indicates that the nested content that is contained within the server control is parsed as controls. |
![]() | ParseAsProperties | Indicates that the nested content that is contained within a server control is parsed as properties of the control. |
| Name | Description | |
|---|---|---|
![]() | _AttributeGetIDsOfNames | Maps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute.) |
![]() | _AttributeGetTypeInfo | Retrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute.) |
![]() | _AttributeGetTypeInfoCount | Retrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute.) |
![]() | _AttributeInvoke | Provides access to properties and methods exposed by an object. (Inherited from Attribute.) |
The ParseChildrenAttribute class allows you to specify parsing logic for a custom server control by marking the server control with the ParseChildrenAttribute metadata attribute.
Marking your server control with the metadata attribute ParseChildren(true) instructs the parser to interpret the elements that are contained within the server control's tags as properties. In this scenario, the ChildrenAsProperties property is true.
Marking your server control with the metadata attribute ParseChildren(true,"<Default Property>") sets the DefaultProperty property to the name of the property that is passed into the attribute.
Marking your server control with the metadata attribute ParseChildren(false), the default value, instructs the parser to interpret the elements that are contained within the server control's tags as content that will be parsed with an associated ControlBuilder that is, as controls. In this scenario, the ChildrenAsProperties property is false.
For information about using attributes, see Extending Metadata Using Attributes.
The code example in this section contains two parts. The first code example demonstrates how to set properties for the ParseChildrenAttribute class. The second code example demonstrates how to use classes in an ASP.NET page.
The following code example demonstrates how to set the ParseChildrenAttribute object of a custom server control named CollectionPropertyControl. The ParseChildrenAttribute sets the ChildrenAsProperties property to true and the DefaultProperty property to the Employee class.
Imports System
Imports System.Collections
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Security.Permissions
Namespace Samples.AspNet.VB.Controls
' The child element class.
<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(ByVal name As String, ByVal title As String, ByVal 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(ByVal value As String)
_name = Value
End Set
End Property
Public Property Title() As String
Get
Return _title
End Get
Set(ByVal value As String)
_title = Value
End Set
End Property
Public Property [Alias]() As String
Get
Return _alias
End Get
Set(ByVal value As String)
_alias = Value
End Set
End Property
End Class 'Employee
' Use the ParseChildren attribute to set the ChildrenAsProperties
' and DefaultProperty properties. Using this constructor, the
' control parses all child controls as properties and must define
' a public property named Employees, which it declares as
' an ArrayList. Nested (child) elements must correspond to
' child elements of the Employees property or to other
' properties of the control.
<ParseChildren(True, "Employees")> _
<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(ByVal value As String)
_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 = System.Drawing.Color.Beige
label.ForeColor = System.Drawing.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 = System.Drawing.Color.Beige
table.ForeColor = System.Drawing.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
End Namespace
using System;
using System.Collections;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Security.Permissions;
namespace Samples.AspNet.CS.Controls
{
// 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 ParseChildren attribute to set the ChildrenAsProperties
// and DefaultProperty properties. Using this constructor, the
// control parses all child controls as properties and must define
// a public property named Employees, which it declares as
// an ArrayList. Nested (child) elements must correspond to
// child elements of the Employees property or to other
// properties of the control.
[ParseChildren(true, "Employees")]
[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 = System.Drawing.Color.Beige;
label.ForeColor = System.Drawing.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 = System.Drawing.Color.Beige;
table.ForeColor = System.Drawing.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. Instances of the Employee class are added declaratively.
<%@ Page Language="VB" %>
<%@ Register TagPrefix="AspSample" Assembly="Samples.AspNet.VB.Controls" Namespace="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)
' Verify attribute values.
Dim p As ParseChildrenAttribute = _
Attribute.GetCustomAttribute(GetType(CollectionPropertyControl), _
GetType(ParseChildrenAttribute))
Dim sb As New StringBuilder()
sb.Append("The DefaultProperty property is " & p.DefaultProperty.ToString() & "<br />")
sb.Append("The ChildrenAsProperties property is " & p.ChildrenAsProperties.ToString() & "<br />")
sb.Append("The IsDefaultAttribute 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:Employee Name="Employee 1"
Title="Title 1"
Alias="Alias 1" />
<AspSample:Employee Name="Employee 2"
Title="Title 2"
Alias="Alias 2" />
</AspSample:CollectionPropertyControl>
</div>
</form>
</body>
</html>
<%@ Page Language="C#" Debug="true" %>
<%@ Register TagPrefix="AspSample" Assembly="Samples.AspNet.CS.Controls" Namespace="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)
{
// Verify attribute values.
ParseChildrenAttribute p =
(ParseChildrenAttribute)Attribute.GetCustomAttribute(typeof(CollectionPropertyControl),
typeof(ParseChildrenAttribute));
StringBuilder sb = new StringBuilder();
sb.Append("The DefaultProperty property is " + p.DefaultProperty.ToString() + "<br />");
sb.Append("The ChildrenAsProperties property is " + p.ChildrenAsProperties.ToString() + "<br />");
sb.Append("The IsDefaultAttribute method returns " + p.IsDefaultAttribute().ToString());
Message.Text = sb.ToString();
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ParseChildrenAttribute Example</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Label ID="Message"
runat="server"/>
<AspSample:CollectionPropertyControl id="CollectionPropertyControl1"
runat="server">
<AspSample:Employee Name="Employee 1"
Title="Title 1"
Alias="Alias 1" />
<AspSample:Employee Name="Employee 2"
Title="Title 2"
Alias="Alias 2" />
</AspSample:CollectionPropertyControl>
</div>
</form>
</body>
</html>
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.
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