TemplatedControlDesigner クラス
テンプレート ベースのサーバー コントロールのデザイン時の動作を拡張します。
この型のすべてのメンバの一覧については、TemplatedControlDesigner メンバ を参照してください。
System.Object
System.ComponentModel.Design.ComponentDesigner
System.Web.UI.Design.HtmlControlDesigner
System.Web.UI.Design.ControlDesigner
System.Web.UI.Design.TemplatedControlDesigner
System.Web.UI.Design.WebControls.BaseDataListDesigner
MustInherit Public Class TemplatedControlDesigner
Inherits ControlDesigner
[C#]
public abstract class TemplatedControlDesigner : ControlDesigner
[C++]
public __gc __abstract class TemplatedControlDesigner : public
ControlDesigner
[JScript]
public abstract class TemplatedControlDesigner extends
ControlDesigner
スレッドセーフ
この型の public static (Visual Basicでは Shared) のすべてのメンバは、マルチスレッド操作で安全に使用できます。インスタンスのメンバの場合は、スレッドセーフであるとは限りません。
解説
Notes to Inheritors[note] TemplatedControlDesigner から継承する場合、 CreateTemplateEditingFrame 、 GetCachedTemplateEditingVerbs 、 GetTemplateContent 、 SetTemplateContent の各メンバをオーバーライドする必要があります。
使用例
[Visual Basic] TemplatedControlDesigner クラスから派生したカスタム デザイナ クラスを作成するコード例を次に示します。このクラスは、 System.Collections.ControlDesigner.AllowResize プロパティと System.Collections.ControlDesigner.DesignTimeHtmlRequiresLoadComplete プロパティ、および GetCachedTemplateEditingVerbs メソッドをオーバーライドします。
' Create a custom designer, named TemplatedListDesigner, that
' derives from the TemplatedControlDesigner class and implements
' the IDataSourceProvider interface.
Imports System
Imports System.Collections
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Data
Imports System.Diagnostics
Imports System.Web.UI
Imports System.Web.UI.Design
Imports System.Web.UI.WebControls
Imports Examples.AspNet
Namespace Examples.AspNet.Design
Public Class TemplatedListDesigner
Inherits TemplatedControlDesigner
Implements IDataSourceProvider
' Declare variables.
Private dummyDataTable As DataTable
Private designTimeDataTable As DataTable
Private templateVerbs() As TemplateEditingVerb
Private templateVerbsDirty As Boolean
' When an instance of this class is created,
' a Boolean property, named templateVerbsDirty,
' is set to True.
Public Sub New()
templateVerbsDirty = True
End Sub
Public Overrides ReadOnly Property AllowResize() As Boolean
Get
' When templates are not defined, render a read-only,
' fixed-size block. Once templates are defined or
' are being edited, the control allows resizing.
Return TemplatesExist Or InTemplateMode
End Get
End Property
' Create a design-time DataSource property that
' tracks to a key with the same name in the control's
' DataBindingCollection.
Public Property DataSource() As String
Get
Dim binding As DataBinding = DataBindings("DataSource")
If Not (binding Is Nothing) Then
Return binding.Expression
End If
Return [String].Empty
End Get
Set
If value Is Nothing Or value.Length = 0 Then
DataBindings.Remove("DataSource")
Else
Dim binding As DataBinding = DataBindings("DataSource")
If binding Is Nothing Then
binding = New DataBinding("DataSource", GetType(IEnumerable), value)
Else
binding.Expression = value
End If
DataBindings.Add(binding)
End If
OnDataSourceChanged()
OnBindingsCollectionChanged("DataSource")
End Set
End Property
' Override the DesignTimeHtmlRequiresLoadComplete property.
Public Overrides ReadOnly Property DesignTimeHtmlRequiresLoadComplete() As Boolean
Get
' If there is a data source, look it up in the container
' and require the document to be loaded completely.
Return DataSource.Length <> 0
End Get
End Property
' Create a read-only property that determines whether the control
' is using templates at design time.
Protected ReadOnly Property TemplatesExist() As Boolean
Get
Return Not (CType(Component, TemplatedList).ItemTemplate Is Nothing)
End Get
End Property
' Override the CreateTemplateEditingFrame method to
' provide a frame in which to manipulate
' templates at design time.
Protected Overrides Function CreateTemplateEditingFrame( _
verb As TemplateEditingVerb) As ITemplateEditingFrame
Dim teService As ITemplateEditingService = _
CType(GetService(GetType(ITemplateEditingService)), ITemplateEditingService)
Debug.Assert( Not (teService Is Nothing), _
"How did we get this far without an ITemplateEditingService?")
Debug.Assert((verb.Index = 0))
Dim templateNames() As String = {"ItemTemplate"}
Dim templateStyles() As Style = {CType(Component, TemplatedList).ItemStyle}
Dim editingFrame As ITemplateEditingFrame = _
teService.CreateFrame( _
Me, verb.Text, templateNames, CType(Component, TemplatedList).ControlStyle, templateStyles)
Return editingFrame
End Function
' Override the Dispose method to release resources associated
' with this designer.
Protected Overloads Overrides Sub Dispose(disposing As Boolean)
If disposing
DisposeTemplateVerbs()
End If
MyBase.Dispose(disposing)
End Sub
' Create a method that releases resources used by the
' designer verbs associated with design-time templates.
Private Sub DisposeTemplateVerbs()
If Not (templateVerbs Is Nothing) Then
templateVerbs(0).Dispose()
templateVerbs = Nothing
templateVerbsDirty = True
End If
End Sub
' Override the GetCachedTemplateEditingVerbs method to check
' whether the verbs have been changed. If they have, a new
' collection of verbs is created for use with this designer.
Protected Overrides Function GetCachedTemplateEditingVerbs() As TemplateEditingVerb()
If templateVerbsDirty = True Then
DisposeTemplateVerbs()
templateVerbs = New TemplateEditingVerb(1) {}
templateVerbs(0) = New TemplateEditingVerb("Item Template", 0, Me)
templateVerbsDirty = False
End If
Return templateVerbs
End Function
Protected Function GetDesignTimeDataSource(minimumRows As Integer, ByRef dummyDataSource As Boolean) As IEnumerable
dummyDataSource = False
Dim selectedDataSource As IEnumerable = CType(Me, IDataSourceProvider).GetResolvedSelectedDataSource()
Dim dataTable As DataTable = designTimeDataTable
' Use the data table corresponding to the selected data source
' if possible.
If dataTable Is Nothing Then
If Not (selectedDataSource Is Nothing) Then
designTimeDataTable = DesignTimeData.CreateSampleDataTable(selectedDataSource)
dataTable = designTimeDataTable
End If
If dataTable Is Nothing Then
' Fall back on a dummy data source if a sample data-table cannot be created.
If dummyDataTable Is Nothing Then
dummyDataTable = DesignTimeData.CreateDummyDataTable()
End If
dataTable = dummyDataTable
dummyDataSource = True
End If
End If
Dim liveDataSource As IEnumerable = DesignTimeData.GetDesignTimeDataSource(dataTable, minimumRows)
Return liveDataSource
End Function
' Override the GetDesignTimeHtml method to display templates
' in the designer if they exist.
Public Overrides Function GetDesignTimeHtml() As String
Dim control As TemplatedList = CType(Component, TemplatedList)
Dim designTimeHtml As String = Nothing
Dim hasATemplate As Boolean = Me.TemplatesExist
If hasATemplate Then
Dim dummyDataSource As Boolean
Dim designTimeDataSource As IEnumerable = GetDesignTimeDataSource(5, dummyDataSource)
Try
control.DataSource = designTimeDataSource
control.DataBind()
designTimeHtml = MyBase.GetDesignTimeHtml()
Finally
control.DataSource = Nothing
End Try
Else
designTimeHtml = GetEmptyDesignTimeHtml()
End If
Return designTimeHtml
End Function
' Override the GetEmptyDesignTimeHtml to check whether
' template mode can be used from the designer, and provide
' display messages for both cases.
Protected Overrides Function GetEmptyDesignTimeHtml() As String
Dim textValue As String
If CanEnterTemplateMode Then
textValue = "Right click and choose a set of templates to edit their content.<br>The ItemTemplate is required."
Else
textValue = "Switch to HTML view to edit the control's templates.<br>The ItemTemplate is required."
End If
Return CreatePlaceHolderDesignTimeHtml(textValue)
End Function
' Override the GetErrorDesignTimeHtml to display an
' error message if an error occurs in design-time rendering of
' the control.
Protected Overrides Function GetErrorDesignTimeHtml(e As Exception) As String
Debug.Fail(e.ToString())
Return CreatePlaceHolderDesignTimeHtml("There was an error rendering the control.<br>Make sure all properties are valid.")
End Function
' Override the GetTemplateContainerDataSource to return the
' data source to be used by the templated control.
Public Overrides Function GetTemplateContainerDataSource(templateName As String) As IEnumerable
Return CType(Me, IDataSourceProvider).GetResolvedSelectedDataSource()
End Function
Public Overrides Function GetTemplateContainerDataItemProperty(templateName As String) As String
Return "DataItem"
End Function
' Override the GetTemplateContent method to return the content
' contained in the template.
Public Overrides Function GetTemplateContent(editingFrame As ITemplateEditingFrame, templateName As String, ByRef allowEditing As Boolean) As String
' Ensure that the designer verb is first in the collection
' and that the name of the template is ItemTemplate.
Debug.Assert((editingFrame.Verb.Index = 0))
Debug.Assert(templateName.Equals("ItemTemplate"))
allowEditing = True
Dim template As ITemplate = CType(Component, TemplatedList).ItemTemplate
Dim templateContent As String = [String].Empty
' If the template is already created, use the text
' already created for it.
If Not (template Is Nothing) Then
templateContent = GetTextFromTemplate(template)
End If
Return templateContent
End Function
' Override the OnComponentChanged method to change
' the control's DataSource or styles in the designer.
Public Overrides Sub OnComponentChanged(sender As Object, e As ComponentChangedEventArgs)
If Not (e.Member Is Nothing) Then
Dim memberName As String = e.Member.Name
If memberName.Equals("DataSource") Or memberName.Equals("DataMember") Then
OnDataSourceChanged()
Else
If memberName.Equals("ItemStyle") Then
OnStylesChanged()
End If
End If
End If
MyBase.OnComponentChanged(sender, e)
End Sub
' Create a method that sets the data table
' associated with the templates to nothing.
Protected Overridable Sub OnDataSourceChanged()
designTimeDataTable = Nothing
End Sub
' Create a method that determines whether the designer
' verbs associated with the control's templates have
' changed.
Protected Sub OnStylesChanged()
OnTemplateEditingVerbsChanged()
End Sub
' Create a method that notifies all callers
' that the designer verbs collection has changed.
Protected Sub OnTemplateEditingVerbsChanged()
templateVerbsDirty = True
End Sub
' Override the PreFilterProperties method to allow the DataSource
' associated with the control to be described in the designer.
Protected Overrides Sub PreFilterProperties(properties As IDictionary)
MyBase.PreFilterProperties(properties)
Dim prop As PropertyDescriptor
prop = CType(properties("DataSource"), PropertyDescriptor)
Debug.Assert(( Not (prop Is Nothing)))
prop = TypeDescriptor.CreateProperty( _
Me.GetType(), prop, New Attribute() {New TypeConverterAttribute(GetType(DataSourceConverter))})
properties("DataSource") = prop
End Sub
' Override the SetTemplateContent method to check whether the template
' exists. If it does, set its content to the value already created for it.
'
Public Overrides Sub SetTemplateContent( _
editingFrame As ITemplateEditingFrame, _
templateName As String, _
templateContent As String)
Debug.Assert((editingFrame.Verb.Index = 0))
Debug.Assert(templateName.Equals("ItemTemplate"))
Dim template As ITemplate = Nothing
If Not (templateContent Is Nothing) And templateContent.Length <> 0 Then
template = GetTemplateFromText(templateContent)
End If
CType(Component, TemplatedList).ItemTemplate = template
End Sub
' Create a method that implements the
' IDataSourceProvider.GetResolvedSelectedDataSource method.
' It converts the object returned from the GetSelectedDataSource
' method into an IEnumberable object to allow iteration over
' the returned object.
Function GetResolvedSelectedDataSource() As IEnumerable _
Implements IDataSourceProvider.GetResolvedSelectedDataSource
Return CType(CType(Me, IDataSourceProvider).GetSelectedDataSource(), IEnumerable)
End Function
' Create a method that implements the
' IDataSourceProvider.GetSelectedDataSource method.
' Return the data source as an IEnumerable object,
' if possible.
Function GetSelectedDataSource() As Object _
Implements IDataSourceProvider.GetSelectedDataSource
Dim selectedDataSource As Object = Nothing
Dim dataSource As String = Nothing
Dim binding As DataBinding = DataBindings("DataSource")
If Not (binding Is Nothing) Then
dataSource = binding.Expression
End If
If Not (dataSource Is Nothing) Then
Dim componentSite As ISite = Component.Site
If Not (componentSite Is Nothing) Then
Dim container As IContainer = CType(componentSite.GetService(GetType(IContainer)), IContainer)
If Not (container Is Nothing) Then
Dim comp As IComponent = container.Components(dataSource)
If TypeOf comp Is IEnumerable Then
selectedDataSource = comp
End If
End If
End If
End If
Return selectedDataSource
End Function
End Class
End Namespace
[C#, C++, JScript] C#、C++、および JScript のサンプルはありません。Visual Basic のサンプルを表示するには、このページの左上隅にある言語のフィルタ ボタン .gif)
をクリックします。
必要条件
名前空間: System.Web.UI.Design
プラットフォーム: Windows 2000, Windows XP Professional, Windows Server 2003 ファミリ
アセンブリ: System.Design (System.Design.dll 内)
参照
TemplatedControlDesigner メンバ | System.Web.UI.Design 名前空間 | IDesigner | ControlDesigner