ParseChildrenAttribute クラス
ASP.NET サーバー コントロールの開発に使用できるメタデータ属性を定義します。ParseChildrenAttribute クラスを使用して、ページに宣言されているサーバー コントロール タグ内に入れ子になっている内容をページ パーサーがどのように処理するかを示します。このクラスは継承できません。
名前空間: System.Web.UI
アセンブリ: System.Web (system.web.dll 内)
構文
解説
使用例
.NET Framework のセキュリティ
継承階層
スレッド セーフ
プラットフォーム
バージョン情報
参照
アセンブリ: System.Web (system.web.dll 内)
構文<AttributeUsageAttribute(AttributeTargets.Class)> _ Public NotInheritable Class ParseChildrenAttribute Inherits Attribute
[AttributeUsageAttribute(AttributeTargets.Class)] public sealed class ParseChildrenAttribute : Attribute
[AttributeUsageAttribute(AttributeTargets::Class)] public ref class ParseChildrenAttribute sealed : public Attribute
解説ParseChildrenAttribute クラスを使用して、カスタム サーバー コントロールを ParseChildrenAttribute メタデータ属性でマークすることにより、サーバー コントロールに対して解析ロジックを指定できます。
サーバー コントロールをメタデータ属性 ParseChildren(true) でマークすると、パーサーは、そのサーバー コントロールのタグ内の要素をプロパティとして解釈します。このシナリオでは、ChildrenAsProperties は true です。
サーバー コントロールをメタデータ属性 ParseChildren(true,"<Default Property>") でマークすると、DefaultProperty プロパティがその属性に渡されるプロパティ名に設定されます。
サーバー コントロールをメタデータ属性 ParseChildren(false) でマークすると (既定値)、パーサーは、サーバー コントロールのタグ内の要素を、関連付けられている ControlBuilder で解析する内容、つまりコントロールとして解釈します。このシナリオでは、ChildrenAsProperties は false です。
属性の使用方法については、「属性を使用したメタデータの拡張」を参照してください。
使用例このセクションには、2 つのコード例が含まれています。最初のコード例では、ParseChildrenAttribute クラスのプロパティを設定する方法を示します。2 番目のコード例では、ASP.NET ページでクラスを使用する方法を示します。
次のコード例では、CollectionPropertyControl というカスタム サーバー コントロールの ParseChildrenAttribute オブジェクトを設定する方法を示します。ParseChildrenAttribute は ChildrenAsProperties プロパティを true に設定し、DefaultProperty プロパティを Employee クラスに設定しています。
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); } } }
package ParseChildrenSamples; // When compiling this class, name it ParseChildren.dll. // Create a namespace that defines two classes: one is a custom control // named Employee, which is created for every instance of a child // element with its name declared in a page associated with this namespace , // and the other, named Employees, that contains these child elements. import System.*; import System.Collections.*; import System.Web.*; import System.Web.UI.*; import System.Web.UI.WebControls.*; // The child element class. public class Employee { private String name; private String title; private String alias; public Employee() { this("", "", ""); } //Employee public Employee(String name, String title, String alias) { this.name = name; this.title = title; this.alias = alias; } //Employee /** @property */ public String get_Name() { return name; } //get_Name /** @property */ public void set_Name(String value) { name = value; } //set_Name /** @property */ public String get_Title() { return title; } //get_Title /** @property */ public void set_Title(String value) { title = value; } //set_Title /** @property */ public String get_Alias() { return alias; } //get_Alias /** @property */ public void set_Alias(String value) { alias = value; } //set_Alias } //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. /** @attribute ParseChildren(true, "Employees") */ public class CollectionPropertyControl extends Control { private String header; private ArrayList employees = new ArrayList(); /** @property */ public String get_Header() { return header; } //get_Header /** @property */ public void set_Header(String value) { header = value; } //set_Header /** @property */ public ArrayList get_Employees() { return employees; } //get_Employees // Override the CreateChildControls method to // add child controls to the Employees property when this // custom control is requested from a page. protected void CreateChildControls() { Label label = new Label(); label.set_Text(get_Header()); label.set_BackColor(System.Drawing.Color.get_Beige()); label.set_ForeColor(System.Drawing.Color.get_Red()); get_Controls().Add(label); get_Controls().Add(new LiteralControl("<BR> <BR>")); Table table = new Table(); TableRow htr = new TableRow(); TableHeaderCell hCell1 = new TableHeaderCell(); hCell1.set_Text("Name"); htr.get_Cells().Add(hCell1); TableHeaderCell hCell2 = new TableHeaderCell(); hCell2.set_Text("Title"); htr.get_Cells().Add(hCell2); TableHeaderCell hCell3 = new TableHeaderCell(); hCell3.set_Text("Alias"); htr.get_Cells().Add(hCell3); table.get_Rows().Add(htr); table.set_BorderWidth(new Unit(2)); table.set_BackColor(System.Drawing.Color.get_Beige()); table.set_ForeColor(System.Drawing.Color.get_Red()); Employee employee = null; for (int iCtr = 0; iCtr < get_Employees().get_Count(); iCtr++) { employee = (Employee)get_Employees().get_Item(iCtr); TableRow tr = new TableRow(); TableCell cell1 = new TableCell(); cell1.set_Text(employee.get_Name()); tr.get_Cells().Add(cell1); TableCell cell2 = new TableCell(); cell2.set_Text(employee.get_Title()); tr.get_Cells().Add(cell2); TableCell cell3 = new TableCell(); cell3.set_Text(employee.get_Alias()); tr.get_Cells().Add(cell3); table.get_Rows().Add(tr); } get_Controls().Add(table); } //CreateChildControls } //CollectionPropertyControl
次のコード例では、CollectionPropertyControl クラスと Employee クラスを ASP.NET ページで使用する方法を示します。Employee クラスのインスタンスが宣言で追加されます。
<%@ 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 > <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 > <head runat="server"> <title>ParseChildrenAttribute Example</title> </head> <body> <form 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>
.NET Framework のセキュリティ継承階層
System.Object
System.Attribute
System.Web.UI.ParseChildrenAttribute
System.Attribute
System.Web.UI.ParseChildrenAttribute
スレッド セーフプラットフォームWindows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。
バージョン情報参照- ParseChildrenAttribute クラスのページへのリンク
