ControlDesigner Class

Definition

Provides a base control designer class for extending the design-mode behavior of a Web server control.

public ref class ControlDesigner : System::Web::UI::Design::HtmlControlDesigner
public class ControlDesigner : System.Web.UI.Design.HtmlControlDesigner
type ControlDesigner = class
    inherit HtmlControlDesigner
Public Class ControlDesigner
Inherits HtmlControlDesigner
Inheritance
Derived

Examples

The following code example demonstrates how to create a simple designer class that derives from the ControlDesigner class. This control designer supports a custom TextControl class and provides a command to change the text size of a control at design time. The control designer is associated with the control by specifying the control designer in a DesignerAttribute object declaration on the TextControl class. The key to persisting property changes from the control designer to the HTML markup is found in the ToggleTextSize method of the custom ActionList class.

To try the example, add a reference to the System.Design.dll assembly and compile the code.

using System;
using System.Web.UI;
using System.Drawing;
using System.Web.UI.Design;
using System.Web.UI.WebControls;
using System.ComponentModel;
using System.ComponentModel.Design;

namespace ASPNet.Design.Samples.CS
{
    // Simple text Web control renders a text string.
    // This control is associated with the TextSizeWebControlDesigner.
    [DesignerAttribute(typeof(TextSizeWebControlDesigner)),
    ToolboxData("<{0}:TextControl runat=\"server\"></{0}:TextControl>")]
    public class TextControl : Label
    {
        private bool _largeText = true;

        // Constructor
        public TextControl()
        {
            Text = "Test Phrase";
            SetSize();
        }

        // Determines whether the text is large or small
        [Bindable(true), Category("Appearance"), DefaultValue("true")]
        public bool LargeText
        {
            get { return _largeText; }
            set
            {
                _largeText = value;
                SetSize();
            }
        }

        // Applies the LargeText property to the control
        private void SetSize()
        {
            if (LargeText)
                this.Font.Size = FontUnit.XLarge;
            else
                this.Font.Size = FontUnit.Small;
        }
    }

    // This control designer offers DesignerActionList commands
    // that can alter the design time html of the associated control.
    public class TextSizeWebControlDesigner : ControlDesigner
    {
        private DesignerActionListCollection _actionLists = null;

        // Do not allow direct resizing of the control
        public override bool AllowResize
        {
            get { return false; }
        }

        // Return a custom ActionList collection
        public override DesignerActionListCollection ActionLists
        {
            get
            {
                if (_actionLists == null)
                {
                    _actionLists = new DesignerActionListCollection();
                    _actionLists.AddRange(base.ActionLists);

                    // Add a custom DesignerActionList
                    _actionLists.Add(new ActionList(this));
                }
                return _actionLists;
            }
        }

        public class ActionList : DesignerActionList
        {
            private TextSizeWebControlDesigner _parent;
            private DesignerActionItemCollection _items;

            // Constructor
            public ActionList(TextSizeWebControlDesigner parent)
                : base(parent.Component)
            {
                _parent = parent;
            }

            // Create the ActionItem collection and add one command
            public override DesignerActionItemCollection GetSortedActionItems()
            {
                if (_items == null)
                {
                    _items = new DesignerActionItemCollection();
                    _items.Add(new DesignerActionMethodItem(this, "ToggleLargeText", "Toggle Text Size", true));
                }
                return _items;
            }

            // ActionList command to change the text size
            private void ToggleLargeText()
            {
                // Get a reference to the parent designer's associated control
                TextControl ctl = (TextControl)_parent.Component;

                // Get a reference to the control's LargeText property
                PropertyDescriptor propDesc = TypeDescriptor.GetProperties(ctl)["LargeText"];

                // Get the current value of the property
                bool v = (bool)propDesc.GetValue(ctl);

                // Toggle the property value
                propDesc.SetValue(ctl, !v);
            }
        }
    }
}
Imports System.Web.UI
Imports System.Web.UI.Design
Imports System.Web.UI.WebControls
Imports System.ComponentModel
Imports System.ComponentModel.Design

Namespace ASPNet.Design.Samples.VB

    ' Simple text Web control renders a text string.
    ' This control is associated with the TextSizeWebControlDesigner.
    <DesignerAttribute(GetType(TextSizeWebControlDesigner)), _
        ToolboxData("<{0}:TextControl runat='server'></{0}:TextControl>")> _
    Public Class TextControl
        Inherits Label

        Private _largeText As Boolean = True

        ' Constructor
        Public Sub New()
            Text = "Test Phrase"
            SetSize()
        End Sub

        ' Determines whether the text is large or small
        <Bindable(True), Category("Appearance"), DefaultValue(True)> _
        Public Property LargeText() As Boolean
            Get
                Return _largeText
            End Get
            Set(ByVal value As Boolean)
                _largeText = value
                SetSize()
            End Set
        End Property

        ' Applies the LargeText property to the control
        Private Sub SetSize()
            If LargeText Then
                Me.Font.Size = FontUnit.XLarge
            Else
                Me.Font.Size = FontUnit.Small
            End If
        End Sub
    End Class


    ' This control designer offers DesignerActionList commands
    ' that can alter the design time html of the associated control.
    Public Class TextSizeWebControlDesigner
        Inherits ControlDesigner

        Private _actionLists As DesignerActionListCollection

        ' Do not allow direct resizing of the control
        Public Overrides ReadOnly Property AllowResize() As Boolean
            Get
                Return False
            End Get
        End Property

        ' Return a custom ActionList collection
        Public Overrides ReadOnly Property ActionLists() As System.ComponentModel.Design.DesignerActionListCollection
            Get
                If IsNothing(_actionLists) Then
                    _actionLists = New DesignerActionListCollection()
                    _actionLists.AddRange(MyBase.ActionLists)

                    ' Add a custom DesignerActionList
                    _actionLists.Add(New ActionList(Me))
                End If

                Return _actionLists
            End Get
        End Property

        ' Create a custom class of DesignerActionList
        Public Class ActionList
            Inherits DesignerActionList
            Private _parent As TextSizeWebControlDesigner
            Private _items As DesignerActionItemCollection

            ' Constructor
            Public Sub New(ByRef parent As TextSizeWebControlDesigner)
                MyBase.New(parent.Component)
                _parent = parent
            End Sub

            ' Create the ActionItem collection and add one command
            Public Overrides Function GetSortedActionItems() As DesignerActionItemCollection
                If IsNothing(_items) Then
                    _items = New DesignerActionItemCollection()
                    _items.Add(New DesignerActionMethodItem(Me, "ToggleLargeText", "Toggle Text Size", True))
                End If

                Return _items
            End Function

            ' ActionList command to change the text size
            Private Sub ToggleLargeText()
                ' Get a reference to the parent designer's associated control
                Dim ctl As TextControl = CType(_parent.Component, TextControl)

                ' Get a reference to the control's LargeText property
                Dim propDesc As PropertyDescriptor = TypeDescriptor.GetProperties(ctl)("LargeText")

                ' Get the current value of the property
                Dim v As Boolean = CType(propDesc.GetValue(ctl), Boolean)
                ' Toggle the property value
                propDesc.SetValue(ctl, (Not v))
            End Sub
        End Class
    End Class
End Namespace
<%@ Page Language="C#" %>
<%@ Register TagPrefix="aspSample" 
    Namespace="ASPNet.Design.Samples.CS" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
    <aspSample:TextControl ID="TextControl1" runat="server">
    </aspSample:TextControl>

    
    </div>
    </form>
</body>
</html>
<%@ Page Language="VB" %>
<%@ Register TagPrefix="aspSample" 
    Namespace="ASPNet.Design.Samples.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>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
        <aspSample:TextControl ID="TextControl1" runat="server">
        </aspSample:TextControl>
    
    </div>
    </form>
</body>
</html>

Remarks

The ControlDesigner class provides a base control designer class that can be inherited from and extended to provide design-time support for a Web server control in a design host, such as Visual Studio 2005.

The object model for working with design-time rendering is improved over earlier versions, with the following new base classes to provide access to the simplified object model:

Automatic Formatting

You can create a variety of automatic and pre-defined formats that can simplify the process of page developers who are applying complex style changes to custom Web server controls. For example, the TableDesigner control, which derives from the ControlDesigner class, provides many automatic formats from which to choose. To implement and provide automatic formatting in your custom controls, use the following features:

Action Lists (Smart Tags)

Action lists are menus of important or widely used tasks that a page developer who uses a control can perform in a design-time user interface (UI), such as Visual Studio 2005. For example, the design-time view of your control could provide a menu of available tasks. This includes a task to format the control automatically. To learn about action lists, start with the following features:

Control Designer Regions

Regions are editable areas in the design-time view of a Web server control. This feature offers WYSIWYG-like editing of the template content, inner controls, and properties at design time. You can have the control designer create controls in regions or you can use the Toolbox to drag and drop controls into regions. Regions are managed with the following features:

Templates

The model for creating a UI for design-time editing of templated controls, such as the GridView control, has been greatly improved from earlier versions. You can create complex custom controls that include templates for various parts of the control, and your custom control designer can help page developers who are modifying templates with the following features:

Design-Time Rendering

The ControlDesigner class has the following methods to support design-time rendering of the Web server control. Most of these methods are the same as in earlier versions:

Constructors

ControlDesigner()

Initializes a new instance of the ControlDesigner class.

Properties

ActionLists

Gets the action list collection for the control designer.

ActionLists

Gets the design-time action lists supported by the component associated with the designer.

(Inherited from ComponentDesigner)
AllowResize

Gets a value indicating whether the control can be resized in the design-time environment.

AssociatedComponents

Gets the collection of components associated with the component managed by the designer.

(Inherited from ComponentDesigner)
AutoFormats

Gets the collection of predefined automatic formatting schemes to display in the Auto Format dialog box for the associated control at design time.

Behavior
Obsolete.

Gets or sets the DHTML behavior that is associated with the designer.

(Inherited from HtmlControlDesigner)
Component

Gets the component this designer is designing.

(Inherited from ComponentDesigner)
DataBindings

Gets the data bindings collection for the current control.

(Inherited from HtmlControlDesigner)
DataBindingsEnabled

Gets a value indicating whether data binding is supported by the containing region for the associated control.

DesignerState

Gets an object that is used to persist data for the associated control at design time.

DesignTimeElement
Obsolete.

Gets the design-time object representing the control that is associated with the HtmlControlDesigner object on the design surface.

(Inherited from HtmlControlDesigner)
DesignTimeElementView
Obsolete.

Gets the view-control object for the control designer.

DesignTimeHtmlRequiresLoadComplete
Obsolete.

Gets a value indicating whether the design host must finish loading before the GetDesignTimeHtml method can be called.

Expressions

Gets the expression bindings for the current control at design time.

(Inherited from HtmlControlDesigner)
HidePropertiesInTemplateMode

Gets a value indicating whether the properties of the associated control are hidden when the control is in template mode.

ID

Gets or sets the ID string for the control.

InheritanceAttribute

Gets an attribute that indicates the type of inheritance of the associated component.

(Inherited from ComponentDesigner)
Inherited

Gets a value indicating whether this component is inherited.

(Inherited from ComponentDesigner)
InTemplateMode

Gets a value indicating whether the control is in either template viewing or editing mode in the design host. The InTemplateMode property is read-only.

IsDirty
Obsolete.

Gets or sets a value indicating whether the Web server control has been marked as changed.

ParentComponent

Gets the parent component for this designer.

(Inherited from ComponentDesigner)
ReadOnly
Obsolete.

Gets or sets a value indicating whether the properties of the control are read-only at design time.

RootDesigner

Gets the control designer for the Web Forms page that contains the associated control.

SetTextualDefaultProperty (Inherited from ComponentDesigner)
ShadowProperties

Gets a collection of property values that override user settings.

(Inherited from ComponentDesigner)
ShouldCodeSerialize
Obsolete.

Gets or sets a value indicating whether to create a field declaration for the control in the code-behind file for the current design document during serialization.

(Inherited from HtmlControlDesigner)
Tag

Gets an object representing the HTML markup element for the associated control.

TemplateGroups

Gets a collection of template groups, each containing one or more template definitions.

UsePreviewControl

Gets a value indicating whether the control designer uses a temporary preview control to generate the design-time HTML markup.

Verbs

Gets the design-time verbs supported by the component that is associated with the designer.

(Inherited from ComponentDesigner)
ViewControl

Gets or sets a Web server control that can be used for previewing the design-time HTML markup.

ViewControlCreated

Gets or sets a value indicating whether a View control has been created for display on the design surface.

Visible

Gets a value that indicates whether the control is visible at design time.

Methods

CreateErrorDesignTimeHtml(String, Exception)

Creates the HTML markup to display a specified exception error message at design time.

CreateErrorDesignTimeHtml(String)

Creates HTML markup to display a specified error message at design time.

CreatePlaceHolderDesignTimeHtml()

Provides a simple rectangular placeholder representation that displays the type and ID of the control.

CreatePlaceHolderDesignTimeHtml(String)

Provides a simple rectangular placeholder representation that displays the type and ID of the control, and also additional specified instructions or information.

CreateViewControl()

Returns a copy of the associated control for viewing or rendering on the design surface.

Dispose()

Releases all resources used by the ComponentDesigner.

(Inherited from ComponentDesigner)
Dispose(Boolean)

Releases the unmanaged resources that are used by the HtmlControlDesigner object and optionally releases the managed resources.

(Inherited from HtmlControlDesigner)
DoDefaultAction()

Creates a method signature in the source code file for the default event on the component and navigates the user's cursor to that location.

(Inherited from ComponentDesigner)
Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetBounds()

Retrieves the coordinates of the rectangle representing the boundaries for the control as displayed on the design surface.

GetDesignTimeHtml()

Retrieves the HTML markup that is used to represent the control at design time.

GetDesignTimeHtml(DesignerRegionCollection)

Retrieves the HTML markup to display the control and populates the collection with the current control designer regions.

GetDesignTimeResourceProviderFactory(IServiceProvider)

Returns an appropriate resource provider factory, depending on the globalization settings in the configuration file for the site.

GetEditableDesignerRegionContent(EditableDesignerRegion)

Returns the content for an editable region of the design-time view of the associated control.

GetEmptyDesignTimeHtml()

Retrieves the HTML markup to represent a Web server control at design time that will have no visual representation at run time.

GetErrorDesignTimeHtml(Exception)

Retrieves the HTML markup that provides information about the specified exception.

GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetPersistenceContent()

Retrieves the persistable inner HTML markup of the control at design time.

GetPersistInnerHtml()
Obsolete.

Retrieves the persistable inner HTML markup of the control.

GetService(Type)

Attempts to retrieve the specified type of service from the design mode site of the designer's component.

(Inherited from ComponentDesigner)
GetType()

Gets the Type of the current instance.

(Inherited from Object)
GetViewRendering()

Retrieves an object that contains the design-time markup for the content and regions of the associated control.

GetViewRendering(Control)

Retrieves an object that contains the design-time markup for the content and regions of the specified control.

GetViewRendering(ControlDesigner)

Retrieves an object that contains the design-time markup for the content and regions of the associated control for the specified control designer.

Initialize(IComponent)

Initializes the control designer and loads the specified component.

InitializeExistingComponent(IDictionary)

Reinitializes an existing component.

(Inherited from ComponentDesigner)
InitializeNewComponent(IDictionary)

Initializes a newly created component.

(Inherited from ComponentDesigner)
InitializeNonDefault()
Obsolete.
Obsolete.

Initializes the settings for an imported component that is already initialized to settings other than the defaults.

(Inherited from ComponentDesigner)
Invalidate()

Invalidates the whole area of the control that is displayed on the design surface and signals the control designer to redraw the control.

Invalidate(Rectangle)

Invalidates the specified area of the control that is displayed on the design surface and signals the control designer to redraw the control.

InvokeGetInheritanceAttribute(ComponentDesigner)

Gets the InheritanceAttribute of the specified ComponentDesigner.

(Inherited from ComponentDesigner)
InvokeTransactedChange(IComponent, TransactedChangeCallback, Object, String, MemberDescriptor)

Wraps a series of changes into a transaction, using the specified parameters that can be rolled back as a unit with the undo functionality of the design host.

InvokeTransactedChange(IComponent, TransactedChangeCallback, Object, String)

Wraps a series of changes into a transaction, using the specified parameters that can be rolled back as a unit with the undo functionality of the design host.

InvokeTransactedChange(IServiceProvider, IComponent, TransactedChangeCallback, Object, String, MemberDescriptor)

Wraps a series of changes into a transaction, using the specified parameters that can be rolled back as a unit with the undo functionality of the design host.

IsPropertyBound(String)
Obsolete.

Retrieves a value indicating whether the specified property on the associated control is data-bound.

Localize(IDesignTimeResourceWriter)

Uses the provided resource writer to persist the localizable properties of the associated control to a resource in the design host.

MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
OnAutoFormatApplied(DesignerAutoFormat)

Called when a predefined, automatic formatting scheme has been applied to the associated control.

OnBehaviorAttached()

Called when the control designer is attached to a Behavior object.

OnBehaviorAttached()
Obsolete.

Called when a behavior is associated with the element.

(Inherited from HtmlControlDesigner)
OnBehaviorDetaching()
Obsolete.

Called when a behavior disassociates from the element.

(Inherited from HtmlControlDesigner)
OnBindingsCollectionChanged(String)
Obsolete.

Called when the data-binding collection changes.

OnClick(DesignerRegionMouseEventArgs)

Called by the design host when the user clicks the associated control at design time.

OnComponentChanged(Object, ComponentChangedEventArgs)

Called when the associated control changes.

OnComponentChanging(Object, ComponentChangingEventArgs)

Represents the method that will handle the ComponentChanging event for the associated control.

OnControlResize()
Obsolete.

Called when the associated Web server control has been resized in the design host at design time.

OnPaint(PaintEventArgs)

Called when the control designer draws the associated control on the design surface, if the CustomPaint value is true.

OnSetComponentDefaults()
Obsolete.
Obsolete.

Sets the default properties for the component.

(Inherited from ComponentDesigner)
OnSetParent()

Provides a way to perform additional processing when the associated control is attached to a parent control.

(Inherited from HtmlControlDesigner)
PostFilterAttributes(IDictionary)

Allows a designer to change or remove items from the set of attributes that it exposes through a TypeDescriptor.

(Inherited from ComponentDesigner)
PostFilterEvents(IDictionary)

Allows a designer to change or remove items from the set of events that it exposes through a TypeDescriptor.

(Inherited from ComponentDesigner)
PostFilterProperties(IDictionary)

Allows a designer to change or remove items from the set of properties that it exposes through a TypeDescriptor.

(Inherited from ComponentDesigner)
PreFilterAttributes(IDictionary)

Allows a designer to add to the set of attributes that it exposes through a TypeDescriptor.

(Inherited from ComponentDesigner)
PreFilterEvents(IDictionary)

Sets the list of events that are exposed at design-time for the TypeDescriptor object for the component.

(Inherited from HtmlControlDesigner)
PreFilterProperties(IDictionary)

Adds properties to or removes properties from the Properties grid in a design host at design time or provides new design-time properties that might correspond to properties on the associated control.

RaiseComponentChanged(MemberDescriptor, Object, Object)

Notifies the IComponentChangeService that this component has been changed.

(Inherited from ComponentDesigner)
RaiseComponentChanging(MemberDescriptor)

Notifies the IComponentChangeService that this component is about to be changed.

(Inherited from ComponentDesigner)
RaiseResizeEvent()
Obsolete.

Raises the OnControlResize() event.

RegisterClone(Object, Object)

Registers internal data in a cloned control.

SetEditableDesignerRegionContent(EditableDesignerRegion, String)

Specifies the content for an editable region of the control at design time.

SetRegionContent(EditableDesignerRegion, String)

Specifies the content for an editable region in the design-time view of the control.

SetViewFlags(ViewFlags, Boolean)

Assigns the specified bitwise ViewFlags enumeration to the specified flag value.

ToString()

Returns a string that represents the current object.

(Inherited from Object)
UpdateDesignTimeHtml()

Refreshes the design-time HTML markup for the associated Web server control by calling the GetDesignTimeHtml method.

Explicit Interface Implementations

IDesignerFilter.PostFilterAttributes(IDictionary)

For a description of this member, see the PostFilterAttributes(IDictionary) method.

(Inherited from ComponentDesigner)
IDesignerFilter.PostFilterEvents(IDictionary)

For a description of this member, see the PostFilterEvents(IDictionary) method.

(Inherited from ComponentDesigner)
IDesignerFilter.PostFilterProperties(IDictionary)

For a description of this member, see the PostFilterProperties(IDictionary) method.

(Inherited from ComponentDesigner)
IDesignerFilter.PreFilterAttributes(IDictionary)

For a description of this member, see the PreFilterAttributes(IDictionary) method.

(Inherited from ComponentDesigner)
IDesignerFilter.PreFilterEvents(IDictionary)

For a description of this member, see the PreFilterEvents(IDictionary) method.

(Inherited from ComponentDesigner)
IDesignerFilter.PreFilterProperties(IDictionary)

For a description of this member, see the PreFilterProperties(IDictionary) method.

(Inherited from ComponentDesigner)
ITreeDesigner.Children

For a description of this member, see the Children property.

(Inherited from ComponentDesigner)
ITreeDesigner.Parent

For a description of this member, see the Parent property.

(Inherited from ComponentDesigner)

Applies to

See also