ParseChildrenAttribute Konstruktoren
Definition
Wichtig
Einige Informationen beziehen sich auf Vorabversionen, die vor dem Release ggf. grundlegend überarbeitet werden. Microsoft übernimmt hinsichtlich der hier bereitgestellten Informationen keine Gewährleistungen, seien sie ausdrücklich oder konkludent.
Initialisiert eine neue Instanz der ParseChildrenAttribute-Klasse.
Überlädt
ParseChildrenAttribute() |
Initialisiert eine neue Instanz der ParseChildrenAttribute-Klasse. |
ParseChildrenAttribute(Boolean) |
Initialisiert eine neue Instanz der ParseChildrenAttribute-Klasse, wobei mithilfe der ChildrenAsProperties-Eigenschaft bestimmt wird, ob die in einem Serversteuerelement enthaltenen Elemente als Eigenschaften des Serversteuerelements analysiert werden. |
ParseChildrenAttribute(Type) |
Initialisiert eine neue Instanz der ParseChildrenAttribute-Klasse, wobei mithilfe der ChildControlType-Eigenschaft bestimmt wird, welche der in einem Serversteuerelement enthaltenen Elemente als Steuerelemente analysiert werden. |
ParseChildrenAttribute(Boolean, String) |
Initialisiert eine neue Instanz der ParseChildrenAttribute-Klasse mithilfe des |
ParseChildrenAttribute()
Initialisiert eine neue Instanz der ParseChildrenAttribute-Klasse.
public:
ParseChildrenAttribute();
public ParseChildrenAttribute ();
Public Sub New ()
Hinweise
Eine neue Instanz der ParseChildrenAttribute -Klasse wird erstellt, wobei die ChildrenAsProperties -Eigenschaft auf false
festgelegt ist.
Weitere Informationen
Gilt für:
ParseChildrenAttribute(Boolean)
Initialisiert eine neue Instanz der ParseChildrenAttribute-Klasse, wobei mithilfe der ChildrenAsProperties-Eigenschaft bestimmt wird, ob die in einem Serversteuerelement enthaltenen Elemente als Eigenschaften des Serversteuerelements analysiert werden.
public:
ParseChildrenAttribute(bool childrenAsProperties);
public ParseChildrenAttribute (bool childrenAsProperties);
new System.Web.UI.ParseChildrenAttribute : bool -> System.Web.UI.ParseChildrenAttribute
Public Sub New (childrenAsProperties As Boolean)
Parameter
- childrenAsProperties
- Boolean
true
, wenn die Elemente des Serversteuerelements als Eigenschaften analysiert werden sollen, andernfalls false
.
Beispiele
Das Codebeispiel in diesem Abschnitt enthält zwei Teile. Im ersten Codebeispiel wird veranschaulicht, wie Eigenschaften für die ParseChildrenAttribute -Klasse festgelegt werden. Im zweiten Codebeispiel wird veranschaulicht, wie Klassen in einer ASP.NET Seite verwendet werden.
Im folgenden Codebeispiel wird veranschaulicht, wie das ParseChildrenAttribute -Objekt für ein benutzerdefiniertes Serversteuerelement namens festgelegt wird CollectionPropertyControl
. Wenn vor ParseChildrenAttribute der -Klasse deklariert wird, die definiert CollectionPropertyControl
, legt die ParseChildrenAttribute - ChildrenAsProperties Eigenschaft auf fest true
.
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
{
// 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 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 this Boolean version of the ParseChildrenAttribute constructor
// to set the ChildrenAsProperties property to true. Any properties of the
// the CollectionPropertyControl custom control will be used as parsable
// children.
[ParseChildren(true)]
[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);
}
}
}
Imports System.Collections
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Security.Permissions
Namespace Samples.AspNet.VB.Controls
' 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
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
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
' Use this Boolean version of the ParseChildrenAttribute constructor
' to set the ChildrenAsProperties property to true. Any properties of the
' the CollectionPropertyControl custom control will be used as parsable
' children.
<ParseChildren(True)> _
<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
End Class
End Namespace ' ParseChildrenSampleVB_2
Im folgenden Codebeispiel wird veranschaulicht, wie die CollectionPropertyControl
Klassen und Employee
in einer ASP.NET Seite verwendet werden. Eine Instanz der Employee
-Klasse wird deklarativ und eine weitere programmgesteuert hinzugefügt.
<%@ Page Language="C#" %>
<%@ 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)
{
// Create a new employee object and add it to the custom control.
Employee e1 = new Employee("Employee 2", "Title 2", "Alias 2");
CollectionPropertyControl1.Employees.Add(e1);
// Verify attribute values.
ParseChildrenAttribute p =
(ParseChildrenAttribute)Attribute.GetCustomAttribute(typeof(CollectionPropertyControl),
typeof(ParseChildrenAttribute));
StringBuilder sb = new StringBuilder();
sb.Append("The ChildControlType property is " + p.ChildControlType.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">
<Employees>
<AspSample:Employee Name="Employee 1"
Title="Title 1"
Alias="Alias 1" />
</Employees>
</AspSample:CollectionPropertyControl>
</div>
</form>
</body>
</html>
<%@ 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)
' Create a new employee object and add it to custom control.
Dim e1 As New Employee("Employee 2", "Title 2", "Alias 2")
CollectionPropertyControl1.Employees.Add(e1)
' Verify attribute values.
Dim p As ParseChildrenAttribute = _
Attribute.GetCustomAttribute(GetType(CollectionPropertyControl), _
GetType(ParseChildrenAttribute))
Dim sb As New StringBuilder()
sb.Append("The ChildControlType property is " & p.ChildControlType.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">
<Employees>
<AspSample:Employee Name="Employee 1"
Title="Title 1"
Alias="Alias 1" />
</Employees>
</AspSample:CollectionPropertyControl>
</div>
</form>
</body>
</html>
Hinweise
Wenn childrenAsProperties
ist false
, werden die elemente, die im Serversteuerelement enthalten sind, als -Steuerelement analysiert.
false
ist die Standardeinstellung für ParseChildrenAttribute.
Weitere Informationen
Gilt für:
ParseChildrenAttribute(Type)
Initialisiert eine neue Instanz der ParseChildrenAttribute-Klasse, wobei mithilfe der ChildControlType-Eigenschaft bestimmt wird, welche der in einem Serversteuerelement enthaltenen Elemente als Steuerelemente analysiert werden.
public:
ParseChildrenAttribute(Type ^ childControlType);
public ParseChildrenAttribute (Type childControlType);
new System.Web.UI.ParseChildrenAttribute : Type -> System.Web.UI.ParseChildrenAttribute
Public Sub New (childControlType As Type)
Parameter
- childControlType
- Type
Der Steuerelementtyp, der als Eigenschaft analysiert werden soll.
Ausnahmen
childControlType
ist null
.
Weitere Informationen
Gilt für:
ParseChildrenAttribute(Boolean, String)
Initialisiert eine neue Instanz der ParseChildrenAttribute-Klasse mithilfe des childrenAsProperties
-Parameters und des defaultProperty
-Parameters.
public:
ParseChildrenAttribute(bool childrenAsProperties, System::String ^ defaultProperty);
public ParseChildrenAttribute (bool childrenAsProperties, string defaultProperty);
new System.Web.UI.ParseChildrenAttribute : bool * string -> System.Web.UI.ParseChildrenAttribute
Public Sub New (childrenAsProperties As Boolean, defaultProperty As String)
Parameter
- childrenAsProperties
- Boolean
true
, wenn die Elemente des Serversteuerelements als Eigenschaften analysiert werden sollen, andernfalls false
.
- defaultProperty
- String
Eine Zeichenfolge, die eine Auflistungseigenschaft des Serversteuerelements definiert, in dem geschachtelter Inhalt standardmäßig analysiert wird.
Beispiele
Das Codebeispiel in diesem Abschnitt enthält zwei Teile. Im ersten Codebeispiel wird veranschaulicht, wie Eigenschaften für die ParseChildrenAttribute -Klasse festgelegt werden. Im zweiten Codebeispiel wird veranschaulicht, wie Klassen in einer ASP.NET Seite verwendet werden.
Im folgenden Codebeispiel wird veranschaulicht, wie das ParseChildrenAttribute Objekt eines benutzerdefinierten Serversteuerelements mit dem Namen festgelegt wird CollectionPropertyControl
. Legt ParseChildrenAttribute die ChildrenAsProperties -Eigenschaft auf true
und die DefaultProperty -Eigenschaft auf die Employee
-Klasse fest.
// 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);
}
}
' 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
End Class
Im folgenden Codebeispiel wird veranschaulicht, wie die CollectionPropertyControl
Klassen und Employee
in einer ASP.NET Seite verwendet werden.
<%@ 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>
<%@ 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>
Hinweise
Wenn childrenAsProperties
ist false
, werden die Elemente als Steuerelemente analysiert.