HtmlSelectBuilder Class
Definition
Important
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Interacts with the parser to build an HtmlSelect control.
public ref class HtmlSelectBuilder : System::Web::UI::ControlBuilderpublic class HtmlSelectBuilder : System.Web.UI.ControlBuildertype HtmlSelectBuilder = class
inherit ControlBuilderPublic Class HtmlSelectBuilder
Inherits ControlBuilder- Inheritance
Examples
The following code example demonstrates how to create a custom HtmlSelectBuilder control that defines two types of <option> child elements of a custom HtmlSelect control and then processes each type differently.
<%@ Page Language="C#"%>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>HtmlSelectBuilder Example</title>
</head>
<body>
<form id="Form1" runat="server">
<h3>HtmlSelectBuilder Example</h3>
<aspSample:CustomHtmlSelect
id="customhtmlselect1"
runat="server">
<aspSample:MyOption1 optionid="option1" value="1" text="item 1"/>
<aspSample:MyOption1 optionid="option2" value="2" text="item 2"/>
<aspSample:MyOption2 optionid="option3" value="3" text="item 3"/>
<aspSample:MyOption2 optionid="option4" value="4" text="item 4"/>
</aspSample:CustomHtmlSelect>
</form>
</body>
</html>
<%@ Page Language="VB"%>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>HtmlSelectBuilder Example</title>
</head>
<body>
<form id="Form1" runat="server">
<h3>HtmlSelectBuilder Example</h3>
<aspSample:CustomHtmlSelect
id="customhtmlselect1"
runat="server">
<aspSample:MyOption1 optionid="option1" value="1" text="item 1"/>
<aspSample:MyOption1 optionid="option2" value="2" text="item 2"/>
<aspSample:MyOption2 optionid="option3" value="3" text="item 3"/>
<aspSample:MyOption2 optionid="option4" value="4" text="item 4"/>
</aspSample:CustomHtmlSelect>
</form>
</body>
</html>
using System;
using System.Security.Permissions;
using System.Collections;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
namespace Samples.AspNet.CS.Controls
{
// Define a type of child control for the custom HtmlSelect control.
public class MyOption1
{
string _id;
string _value;
string _text;
public string optionid
{
get
{ return _id; }
set
{ _id = value; }
}
public string value
{
get
{ return _value; }
set
{ _value = value; }
}
public string text
{
get
{ return _text; }
set
{ _text = value; }
}
}
// Define a type of child control for the custom HtmlSelect control.
public class MyOption2
{
string _id;
string _value;
string _text;
public string optionid
{
get
{ return _id; }
set
{ _id = value; }
}
public string value
{
get
{ return _value; }
set
{ _value = value; }
}
public string text
{
get
{ return _text; }
set
{ _text = value; }
}
}
// Define a custom HtmlSelectBuilder control.
public class MyHtmlSelectBuilder : HtmlSelectBuilder
{
[AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
public override Type GetChildControlType(string tagName, IDictionary attribs)
{
// Distinguish between two possible types of child controls.
if (tagName.ToLower().EndsWith("myoption1"))
{
return typeof(MyOption1);
}
else if (tagName.ToLower().EndsWith("myoption2"))
{
return typeof(MyOption2);
}
return null;
}
}
[ControlBuilderAttribute(typeof(MyHtmlSelectBuilder))]
public class CustomHtmlSelect : HtmlSelect
{
// Override AddParsedSubObject to treat the two types
// of child controls differently.
protected override void AddParsedSubObject(object obj)
{
string _outputtext;
if (obj is MyOption1)
{
_outputtext = "option group 1: " + ((MyOption1)obj).text;
ListItem li = new ListItem(_outputtext, ((MyOption1)obj).value);
base.Items.Add(li);
}
if (obj is MyOption2)
{
_outputtext = "option group 2: " + ((MyOption2)obj).text;
ListItem li = new ListItem(_outputtext, ((MyOption2)obj).value);
base.Items.Add(li);
}
}
}
}
Imports System.Security.Permissions
Imports System.Collections
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Web.UI.HtmlControls
Namespace Samples.AspNet.VB.Controls
' Define a type of child control for the custom HtmlSelect control.
Public Class MyOption1
Private _id As String
Private _value As String
Private _text As String
Public Property optionid() As String
Get
Return _id
End Get
Set(ByVal value As String)
_id = value
End Set
End Property
Public Property value() As String
Get
Return _value
End Get
Set(ByVal value As String)
_value = 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
End Class
' Define a type of child control for the custom HtmlSelect control.
Public Class MyOption2
Private _id As String
Private _value As String
Private _text As String
Public Property optionid() As String
Get
Return _id
End Get
Set(ByVal value As String)
_id = value
End Set
End Property
Public Property value() As String
Get
Return _value
End Get
Set(ByVal value As String)
_value = 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
End Class
' Define a custom HtmlSelectBuilder control.
Public Class MyHtmlSelectBuilder
Inherits HtmlSelectBuilder
<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public Overrides Function GetChildControlType(ByVal tagName As String, ByVal attribs As IDictionary) As Type
' Distinguish between two possible types of child controls.
If tagName.ToLower().EndsWith("myoption1") Then
Return GetType(MyOption1)
ElseIf tagName.ToLower().EndsWith("myoption2") Then
Return GetType(MyOption2)
End If
Return Nothing
End Function
End Class
<ControlBuilderAttribute(GetType(MyHtmlSelectBuilder))> _
Public Class CustomHtmlSelect
Inherits HtmlSelect
' Override AddParsedSubObject to treat the two types
' of child controls differently.
Protected Overrides Sub AddParsedSubObject(ByVal obj As Object)
Dim _outputtext As String
If TypeOf obj Is MyOption1 Then
_outputtext = "option group 1: " + CType(obj, MyOption1).text
Dim li As New ListItem(_outputtext, CType(obj, MyOption1).value)
MyBase.Items.Add(li)
End If
If TypeOf obj Is MyOption2 Then
_outputtext = "option group 2: " + CType(obj, MyOption2).text
Dim li As New ListItem(_outputtext, CType(obj, MyOption2).value)
MyBase.Items.Add(li)
End If
End Sub
End Class
End Namespace
Remarks
The HtmlSelectBuilder control interacts with the page parser to build an HtmlSelect control. Use the HtmlSelectBuilder control to customize the parsing of an HtmlSelect control.
The AllowWhitespaceLiterals property is set to false so that white space is always ignored. Use the GetChildControlType method to determine the type of the HtmlSelect control's child controls.
Notes to Inheritors
To create a custom control builder for an HtmlSelect control, you need to inherit from this class.
Constructors
| HtmlSelectBuilder() |
Initializes a new instance of the HtmlSelectBuilder class. |
Properties
| BindingContainerBuilder |
Gets the control builder that corresponds to the binding container for the control that this builder creates. (Inherited from ControlBuilder) |
| BindingContainerType |
Gets the type of the binding container for the control that this builder creates. (Inherited from ControlBuilder) |
| ComplexPropertyEntries |
Gets a collection of complex property entries. (Inherited from ControlBuilder) |
| ControlType |
Gets the Type for the control to be created. (Inherited from ControlBuilder) |
| CurrentFilterResolutionService |
Gets an IFilterResolutionService object that is used to manage device-filter related services when parsing and persisting controls in the designer. (Inherited from ControlBuilder) |
| DeclareType |
Gets the type that will be used by code generation to declare the control. (Inherited from ControlBuilder) |
| FChildrenAsProperties |
Gets a value that determines whether the control has a ParseChildrenAttribute with ChildrenAsProperties set to |
| FIsNonParserAccessor |
Gets a value that determines whether the control implements the IParserAccessor interface. (Inherited from ControlBuilder) |
| HasAspCode |
Gets a value indicating whether the control contains any code blocks. (Inherited from ControlBuilder) |
| ID |
Gets or sets the identifier property for the control to be built. (Inherited from ControlBuilder) |
| InDesigner |
Returns whether the ControlBuilder is running in the designer. (Inherited from ControlBuilder) |
| InPageTheme |
Gets a Boolean value indicating whether this ControlBuilder object is used to generate page themes. (Inherited from ControlBuilder) |
| ItemType |
Gets the type set on the binding container. (Inherited from ControlBuilder) |
| Localize |
Gets a Boolean value indicating whether the control that is created by this ControlBuilder object is localized. (Inherited from ControlBuilder) |
| NamingContainerType |
Gets the type of the naming container for the control that this builder creates. (Inherited from ControlBuilder) |
| PageVirtualPath |
Gets the virtual path of a page to be built by this ControlBuilder instance. (Inherited from ControlBuilder) |
| Parser |
Gets the TemplateParser responsible for parsing the control. (Inherited from ControlBuilder) |
| ServiceProvider |
Gets the service object for this ControlBuilder object. (Inherited from ControlBuilder) |
| SubBuilders |
Gets a list of child ControlBuilder objects for this ControlBuilder object. (Inherited from ControlBuilder) |
| TagName |
Gets the tag name for the control to be built. (Inherited from ControlBuilder) |
| TemplatePropertyEntries |
Gets a collection of template property entries. (Inherited from ControlBuilder) |
| ThemeResolutionService |
Gets an IThemeResolutionService object that is used in design time to manage control themes and skins. (Inherited from ControlBuilder) |
Methods
| AllowWhitespaceLiterals() |
Determines whether the white space literals in an HtmlSelect control are to be processed or ignored. |
| AppendLiteralString(String) |
Adds the specified literal content to a control. This method is called by the ASP.NET page framework. (Inherited from ControlBuilder) |
| AppendSubBuilder(ControlBuilder) |
Adds builders to the ControlBuilder object for any child controls that belong to the container control. (Inherited from ControlBuilder) |
| BuildObject() |
Builds a design-time instance of the control that is referred to by this ControlBuilder object. (Inherited from ControlBuilder) |
| CloseControl() |
Called by the parser to inform the builder that the parsing of the control's opening and closing tags is complete. (Inherited from ControlBuilder) |
| Equals(Object) |
Determines whether the specified object is equal to the current object. (Inherited from Object) |
| GetChildControlType(String, IDictionary) |
Obtains the Type for the HtmlSelect control's child controls. |
| GetHashCode() |
Serves as the default hash function. (Inherited from Object) |
| GetObjectPersistData() |
Creates the ObjectPersistData object for this ControlBuilder object. (Inherited from ControlBuilder) |
| GetResourceKey() |
Retrieves the resource key for this ControlBuilder object. (Inherited from ControlBuilder) |
| GetType() |
Gets the Type of the current instance. (Inherited from Object) |
| HasBody() |
Determines if a control has both an opening and closing tag. This method is called by the ASP.NET page framework. (Inherited from ControlBuilder) |
| HtmlDecodeLiterals() |
Determines whether the literal string of an HTML control must be HTML decoded. This method is called by the ASP.NET page framework. (Inherited from ControlBuilder) |
| Init(TemplateParser, ControlBuilder, Type, String, String, IDictionary) |
Initializes the ControlBuilder for use after it is instantiated. This method is called by the ASP.NET page framework. (Inherited from ControlBuilder) |
| MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
| NeedsTagInnerText() |
Determines if the control builder needs to get its inner text. If so, the SetTagInnerText(String) method must be called. This method is called by the ASP.NET page framework. (Inherited from ControlBuilder) |
| OnAppendToParentBuilder(ControlBuilder) |
Notifies the ControlBuilder that it is being added to a parent control builder. (Inherited from ControlBuilder) |
| ProcessGeneratedCode(CodeCompileUnit, CodeTypeDeclaration, CodeTypeDeclaration, CodeMemberMethod, CodeMemberMethod) |
Enables custom control builders to access the generated Code Document Object Model (CodeDom) and insert and modify code during the process of parsing and building controls. (Inherited from ControlBuilder) |
| SetResourceKey(String) |
Sets the resource key for this ControlBuilder object. (Inherited from ControlBuilder) |
| SetServiceProvider(IServiceProvider) |
Sets the service object for this ControlBuilder object. (Inherited from ControlBuilder) |
| SetTagInnerText(String) |
Provides the ControlBuilder with the inner text of the control tag. (Inherited from ControlBuilder) |
| ToString() |
Returns a string that represents the current object. (Inherited from Object) |
