TemplateDefinition Class (System.Web.UI.Design)

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TemplateDefinition Class
Provides properties and methods that define a template element in a Web server control at design time.

Namespace: System.Web.UI.Design
Assembly: System.Design (in system.design.dll)

Syntax

Visual Basic (Declaration)
Public Class TemplateDefinition
	Inherits DesignerObject
Visual Basic (Usage)
Dim instance As TemplateDefinition

C#
public class TemplateDefinition : DesignerObject
C++
public ref class TemplateDefinition : public DesignerObject
J#
public class TemplateDefinition extends DesignerObject
JScript
public class TemplateDefinition extends DesignerObject
XAML
Not applicable.
Remarks

The TemplateDefinition class provides a base template definition class that can be inherited from and extended for a control designer to use in providing support for templated controls in a design host such as Visual Studio 2005. A design host uses the properties and methods of the TemplateDefinition class to facilitate creating and editing a template at design time.

Example

The following code example demonstrates how to derive a custom class from the ControlDesigner class. This control designer supports a control with four possible templates.

To try it, add a reference to the System.Design.dll assembly, compile the code, and then, in a design host such as Visual Studio 2005, look at the page in Design view. Select the control, click the action list to select a template to modify, and then use the drag-and-drop feature to move controls into the template.

Visual Basic
Imports Microsoft.VisualBasic
Imports System
Imports System.ComponentModel
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Web.UI.Design

Namespace ASPNet.Design.Samples

    ' Set an attribute reference to the designer, and define 
    ' the HTML markup that the toolbox will write into the source.
    <Designer(GetType(TemplateGroupsSampleDesigner)), _
        ToolboxData("<{0}:TemplateGroupsSample runat=server></{0}:TemplateGroupsSample>")> _
    Public Class TemplateGroupsSample
        Inherits WebControl
        Implements INamingContainer

        ' Field for the templates
        Private _templates() As ITemplate

        ' Constructor
        Public Sub New()
            ReDim _templates(4)
        End Sub

        ' For each template property, set the designer attributes 
        ' so the property does not appear in the property grid, but 
        ' changes to the template are persisted in the control.
        <Browsable(False), _
            PersistenceMode(PersistenceMode.InnerProperty)> _
        Public Property Template1() As ITemplate
            Get
                Return _templates(0)
            End Get
            Set(ByVal Value As ITemplate)
                _templates(0) = Value
            End Set
        End Property
        <Browsable(False), _
            PersistenceMode(PersistenceMode.InnerProperty)> _
        Public Property Template2() As ITemplate
            Get
                Return _templates(1)
            End Get
            Set(ByVal Value As ITemplate)
                _templates(1) = Value
            End Set
        End Property
        <Browsable(False), _
            PersistenceMode(PersistenceMode.InnerProperty)> _
        Public Property Template3() As ITemplate
            Get
                Return _templates(2)
            End Get
            Set(ByVal Value As ITemplate)
                _templates(2) = Value
            End Set
        End Property
        <Browsable(False), _
            PersistenceMode(PersistenceMode.InnerProperty)> _
        Public Property Template4() As ITemplate
            Get
                Return _templates(3)
            End Get
            Set(ByVal Value As ITemplate)
                _templates(3) = Value
            End Set
        End Property

        Protected Overrides Sub CreateChildControls()
            ' Instantiate the template inside the panel
            ' then add the panel to the Controls collection
            Dim i As Integer

            For i = 0 To 3
                Dim pan As New Panel()
                _templates(i).InstantiateIn(pan)
                Me.Controls.Add(pan)
            Next
        End Sub

    End Class

    ' Designer for the TemplateGroupsSample class
    Public Class TemplateGroupsSampleDesigner
        Inherits System.Web.UI.Design.ControlDesigner

        Private col As TemplateGroupCollection = Nothing

        Public Overrides Sub Initialize(ByVal Component As IComponent)
            ' Initialize the base
            MyBase.Initialize(Component)
            ' Turn on template editing
            SetViewFlags(ViewFlags.TemplateEditing, True)
        End Sub

        ' Add instructions to the placeholder view of the control
        Public Overloads Overrides Function GetDesignTimeHtml() As String
            Return CreatePlaceHolderDesignTimeHtml("Click here and use " & _
                "the task menu to edit the templates.")
        End Function

        Public Overrides ReadOnly Property TemplateGroups() As TemplateGroupCollection
            Get
                If IsNothing(col) Then
                    ' Get the base collection
                    col = MyBase.TemplateGroups

                    ' Create variables
                    Dim tempGroup As TemplateGroup
                    Dim tempDef As TemplateDefinition
                    Dim ctl As TemplateGroupsSample

                    ' Get reference to the component as TemplateGroupsSample
                    ctl = CType(Component, TemplateGroupsSample)

                    ' Create a TemplateGroup
                    tempGroup = New TemplateGroup("Template Set A")

                    ' Create a TemplateDefinition
                    tempDef = New TemplateDefinition(Me, "Template A1", ctl, "Template1", True)

                    ' Add the TemplateDefinition to the TemplateGroup
                    tempGroup.AddTemplateDefinition(tempDef)

                    ' Create another TemplateDefinition
                    tempDef = New TemplateDefinition(Me, "Template A2", ctl, "Template2", True)

                    ' Add the TemplateDefinition to the TemplateGroup
                    tempGroup.AddTemplateDefinition(tempDef)

                    ' Add the TemplateGroup to the TemplateGroupCollection
                    col.Add(tempGroup)

                    ' Create another TemplateGroup and populate it
                    tempGroup = New TemplateGroup("Template Set B")
                    tempDef = New TemplateDefinition(Me, "Template B1", ctl, "Template3", True)
                    tempGroup.AddTemplateDefinition(tempDef)
                    tempDef = New TemplateDefinition(Me, "Template B2", ctl, "Template4", True)
                    tempGroup.AddTemplateDefinition(tempDef)

                    ' Add the TemplateGroup to the TemplateGroupCollection
                    col.Add(tempGroup)
                End If

                Return col
            End Get
        End Property

        ' Do not allow direct resizing unless in TemplateMode
        Public Overrides ReadOnly Property AllowResize() As Boolean
            Get
                If Me.InTemplateMode Then
                    Return True
                Else
                    Return False
                End If
            End Get
        End Property
    End Class
End Namespace

	...

<%@ Page Language="VB" %>
<%@ Register TagPrefix="aspSample" 
    Namespace="ASPNet.Design.Samples" %>

<!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>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
       <aspSample:TemplateGroupsSample runat="server" ID="TGSample1">
       </aspSample:TemplateGroupsSample>
    
    </div>
    </form>
</body>
</html>

C#
using System;
using System.ComponentModel;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.Design;

namespace ASPNet.Design.Samples
{
    // Set an attribute reference to the designer, and define 
    // the HTML markup that the toolbox will write into the source.
    [Designer(typeof(TemplateGroupsSampleDesigner)),
        ToolboxData("<{0}:TemplateGroupsSample runat=server></{0}:TemplateGroupsSample>")]
    public sealed class TemplateGroupsSample : WebControl, INamingContainer
    {
        // Field for the templates
        private ITemplate[] _templates;

        // Constructor
        public TemplateGroupsSample()
        {
            _templates = new ITemplate[4];
        }

        // For each template property, set the designer attributes 
        // so the property does not appear in the property grid, but 
        // changes to the template are persisted in the control.
        [Browsable(false),
            PersistenceMode(PersistenceMode.InnerProperty)]
        public ITemplate Template1
        {
            get { return _templates[0]; }
            set { _templates[0] = value; }
        }
        [Browsable(false),
            PersistenceMode(PersistenceMode.InnerProperty)]
        public ITemplate Template2
        {
            get { return _templates[1]; }
            set { _templates[1] = value; }
        }
        [Browsable(false),
            PersistenceMode(PersistenceMode.InnerProperty)]
        public ITemplate Template3
        {
            get { return _templates[2]; }
            set { _templates[2] = value; }
        }
        [Browsable(false),
            PersistenceMode(PersistenceMode.InnerProperty)]
        public ITemplate Template4
        {
            get { return _templates[3]; }
            set { _templates[3] = value; }
        }

        protected override void CreateChildControls()
        {
            // Instantiate each template inside a panel
            // then add the panel to the Controls collection
            for (int i = 0; i < 4; i++)
            {
                Panel pan = new Panel();
                _templates[i].InstantiateIn(pan);
                this.Controls.Add(pan);
            }
        }
    }

    // Designer for the TemplateGroupsSample control
    public class TemplateGroupsSampleDesigner : ControlDesigner
    {
        TemplateGroupCollection col = null;

        public override void Initialize(IComponent component)
        {
            // Initialize the base
            base.Initialize(component);
            // Turn on template editing
            SetViewFlags(ViewFlags.TemplateEditing, true);
        }

        // Add instructions to the placeholder view of the control
        public override string GetDesignTimeHtml()
        {
            return CreatePlaceHolderDesignTimeHtml("Click here and use " +
                "the task menu to edit the templates.");
        }

        public override TemplateGroupCollection TemplateGroups
        {
            get
            {

                if (col == null)
                {
                    // Get the base collection
                    col = base.TemplateGroups;

                    // Create variables
                    TemplateGroup tempGroup;
                    TemplateDefinition tempDef;
                    TemplateGroupsSample ctl;

                    // Get reference to the component as TemplateGroupsSample
                    ctl = (TemplateGroupsSample)Component;

                    // Create a TemplateGroup
                    tempGroup = new TemplateGroup("Template Set A");

                    // Create a TemplateDefinition
                    tempDef = new TemplateDefinition(this, "Template A1", 
                        ctl, "Template1", true);

                    // Add the TemplateDefinition to the TemplateGroup
                    tempGroup.AddTemplateDefinition(tempDef);

                    // Create another TemplateDefinition
                    tempDef = new TemplateDefinition(this, "Template A2", 
                        ctl, "Template2", true);

                    // Add the TemplateDefinition to the TemplateGroup
                    tempGroup.AddTemplateDefinition(tempDef);

                    // Add the TemplateGroup to the TemplateGroupCollection
                    col.Add(tempGroup);

                    // Create another TemplateGroup and populate it
                    tempGroup = new TemplateGroup("Template Set B");
                    tempDef = new TemplateDefinition(this, "Template B1", 
                        ctl, "Template3", true);
                    tempGroup.AddTemplateDefinition(tempDef);
                    tempDef = new TemplateDefinition(this, "Template B2", 
                        ctl, "Template4", true);
                    tempGroup.AddTemplateDefinition(tempDef);

                    // Add the TemplateGroup to the TemplateGroupCollection
                    col.Add(tempGroup);
                }

                return col;
            }
        }

        // Do not allow direct resizing unless in TemplateMode
        public override bool AllowResize
        {
            get
            {
                if (this.InTemplateMode)
                    return true;
                else
                    return false;
            }
        }
    }
}

Inheritance Hierarchy

System.Object
   System.Web.UI.Design.DesignerObject
    System.Web.UI.Design.TemplateDefinition
Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Platforms

Windows 98, Windows Server 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

Version Information

.NET Framework

Supported in: 3.0, 2.0
See Also