LabelDesigner Class

Reference

Definition

Namespace:: System.Web.UI.Design.WebControls

Assembly:: System.Design.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Provides design-time support in a visual designer for the Label Web server control.

public ref class LabelDesigner : System::Web::UI::Design::TextControlDesigner

public class LabelDesigner : System.Web.UI.Design.TextControlDesigner

[System.Web.UI.Design.SupportsPreviewControl(true)]
public class LabelDesigner : System.Web.UI.Design.TextControlDesigner

type LabelDesigner = class
    inherit TextControlDesigner

[<System.Web.UI.Design.SupportsPreviewControl(true)>]
type LabelDesigner = class
    inherit TextControlDesigner

Public Class LabelDesigner
Inherits TextControlDesigner

Inheritance: Object

ComponentDesigner

HtmlControlDesigner

ControlDesigner

TextControlDesigner
LabelDesigner

Attributes: SupportsPreviewControlAttribute

Examples

The following code example shows how to derive the SampleLabel control from the Label control, and applies a DesignerAttribute attribute on the SampleLabel control to associate it with the SampleLabelDesigner class.

The code example also derives the SampleLabelDesigner from the LabelDesigner class. It overrides the GetDesignTimeHtml method to set the BorderStyle property to Dashed, if the original BorderStyle was the NotSet or None value. This improves the visibility of the associated control at design time.

using System;
using System.Web;
using System.Web.UI.WebControls;
using System.Web.UI.Design.WebControls;
using System.ComponentModel;
using System.Security.Permissions;

namespace Examples.CS.WebControls.Design
{
    // The SampleLabel is a copy of the Label.
    [AspNetHostingPermission(SecurityAction.Demand, 
        Level = AspNetHostingPermissionLevel.Minimal)]
    [AspNetHostingPermission(SecurityAction.InheritanceDemand, 
        Level = AspNetHostingPermissionLevel.Minimal)]
    [Designer(typeof(Examples.CS.WebControls.Design.SampleLabelDesigner))]
    public class SampleLabel : Label
    {
    } // SampleLabel

    // Override members of the LabelDesigner.
    public class SampleLabelDesigner : LabelDesigner
    {
        // Generate the design-time markup.
        public override string GetDesignTimeHtml()
        {
            // Make the control more visible in the designer.  If the border 
            // style is None or NotSet, change the border to a dashed line. 
            SampleLabel sampleLabel = (SampleLabel)Component;
            string designTimeMarkup = null;

            // Check if the border style should be changed.
            if (sampleLabel.BorderStyle == BorderStyle.NotSet ||
                sampleLabel.BorderStyle == BorderStyle.None)
            {
                BorderStyle oldBorderStyle = sampleLabel.BorderStyle;

                try
                {
                    // Set the design-time BorderStyle.
                    sampleLabel.BorderStyle = BorderStyle.Dashed;

                    // Call the base method to generate the markup.
                    designTimeMarkup = base.GetDesignTimeHtml();
                }
                catch (Exception ex)
                {
                    // If an exception occurs, generate an error message.
                    designTimeMarkup = GetErrorDesignTimeHtml(ex);
                }
                finally
                {
                    // Restore the BorderStyle to its original setting.
                    sampleLabel.BorderStyle = oldBorderStyle;
                }
            }
            else
            {
                // Call the base method to generate the markup.
                designTimeMarkup = base.GetDesignTimeHtml();
            }

            return designTimeMarkup;
        } // GetDesignTimeHtml
    } // SampleLabelDesigner
} // Examples.CS.WebControls.Design

Imports System.Web
Imports System.ComponentModel
Imports System.Web.UI.WebControls
Imports System.Web.UI.Design.WebControls
Imports System.Security.Permissions

Namespace Examples.VB.WebControls.Design

    ' The SampleLabel is a copy of the Label.
    <AspNetHostingPermission(SecurityAction.Demand, _
        Level:=AspNetHostingPermissionLevel.Minimal)> _
    <AspNetHostingPermission(SecurityAction.InheritanceDemand, _
        Level:=AspNetHostingPermissionLevel.Minimal)> _
    <Designer(GetType(Examples.VB.WebControls.Design.SampleLabelDesigner))> _
    Public Class SampleLabel
        Inherits Label
    End Class

    ' Override members of the LabelDesigner.
    Public Class SampleLabelDesigner
        Inherits LabelDesigner

        ' Generate the design-time markup.
        Public Overrides Function GetDesignTimeHtml() As String

            ' Make the control more visible in the designer.  If the border 
            ' style is None or NotSet, change the border to a dashed line. 
            Dim sampleLabel As SampleLabel = CType(Component, SampleLabel)
            Dim designTimeMarkup As String = Nothing

            ' Check if the border style should be changed.
            If (sampleLabel.BorderStyle = BorderStyle.NotSet Or _
                sampleLabel.BorderStyle = BorderStyle.None) Then

                Dim oldBorderStyle As BorderStyle = sampleLabel.BorderStyle

                Try
                    ' Set the design-time BorderStyle.
                    sampleLabel.BorderStyle = BorderStyle.Dashed

                    ' Call the base method to generate the markup.
                    designTimeMarkup = MyBase.GetDesignTimeHtml()

                Catch ex As Exception
                    ' If an exception occurs, generate an error message.
                    designTimeMarkup = GetErrorDesignTimeHtml(ex)

                Finally
                    ' Restore the BorderStyle to its original setting.
                    sampleLabel.BorderStyle = oldBorderStyle
                End Try

            Else
                ' Call the base method to generate the markup.
                designTimeMarkup = MyBase.GetDesignTimeHtml()
            End If

            Return designTimeMarkup
        End Function ' GetDesignTimeHtml
    End Class
End Namespace ' Examples.VB.WebControls.Design

Remarks

The Label control allows text to be displayed programmatically on a Web page.

In a visual designer, when you switch from Source to Design view, the markup source code that describes a Label control is parsed and a design-time version of the control is created on the design surface. When you switch back to Source view, the design-time control is persisted to the markup source code and edited into the markup for the Web page. The LabelDesigner class provides design-time support for the Label control.

The OnComponentChanged method is called when there is a change to the associated Label control.

Constructors

LabelDesigner()

Initializes a new instance of the LabelDesigner class.

Properties

ActionLists	Gets the action list collection for the control designer. (Inherited from ControlDesigner)
AllowResize	Gets a value indicating whether the control can be resized in the design-time environment. (Inherited from ControlDesigner)
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. (Inherited from ControlDesigner)
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. (Inherited from ControlDesigner)
DesignerState	Gets an object that is used to persist data for the associated control at design time. (Inherited from ControlDesigner)
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. (Inherited from ControlDesigner)
DesignTimeHtmlRequiresLoadComplete	Obsolete. Gets a value indicating whether the design host must finish loading before the GetDesignTimeHtml method can be called. (Inherited from ControlDesigner)
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. (Inherited from ControlDesigner)
ID	Gets or sets the ID string for the control. (Inherited from ControlDesigner)
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. (Inherited from ControlDesigner)
IsDirty	Obsolete. Gets or sets a value indicating whether the Web server control has been marked as changed. (Inherited from ControlDesigner)
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. (Inherited from ControlDesigner)
RootDesigner	Gets the control designer for the Web Forms page that contains the associated control. (Inherited from ControlDesigner)
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. (Inherited from ControlDesigner)
TemplateGroups	Gets a collection of template groups, each containing one or more template definitions. (Inherited from ControlDesigner)
UsePreviewControl	Gets a value indicating whether the control designer uses a temporary preview control to generate the design-time HTML markup. (Inherited from ControlDesigner)
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. (Inherited from ControlDesigner)
ViewControlCreated	Gets or sets a value indicating whether a `View` control has been created for display on the design surface. (Inherited from ControlDesigner)
Visible	Gets a value that indicates whether the control is visible at design time. (Inherited from ControlDesigner)

Methods

CreateErrorDesignTimeHtml(String, Exception)	Creates the HTML markup to display a specified exception error message at design time. (Inherited from ControlDesigner)
CreateErrorDesignTimeHtml(String)	Creates HTML markup to display a specified error message at design time. (Inherited from ControlDesigner)
CreatePlaceHolderDesignTimeHtml()	Provides a simple rectangular placeholder representation that displays the type and ID of the control. (Inherited from ControlDesigner)
CreatePlaceHolderDesignTimeHtml(String)	Provides a simple rectangular placeholder representation that displays the type and ID of the control, and also additional specified instructions or information. (Inherited from ControlDesigner)
CreateViewControl()	Returns a copy of the associated control for viewing or rendering on the design surface. (Inherited from ControlDesigner)
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. (Inherited from ControlDesigner)
GetDesignTimeHtml()	Gets the markup that is used to represent the associated control at design time. (Inherited from TextControlDesigner)
GetDesignTimeHtml(DesignerRegionCollection)	Retrieves the HTML markup to display the control and populates the collection with the current control designer regions. (Inherited from ControlDesigner)
GetEditableDesignerRegionContent(EditableDesignerRegion)	Returns the content for an editable region of the design-time view of the associated control. (Inherited from ControlDesigner)
GetEmptyDesignTimeHtml()	Retrieves the HTML markup to represent a Web server control at design time that will have no visual representation at run time. (Inherited from ControlDesigner)
GetErrorDesignTimeHtml(Exception)	Retrieves the HTML markup that provides information about the specified exception. (Inherited from ControlDesigner)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetPersistenceContent()	Retrieves the persistable inner HTML markup of the control at design time. (Inherited from ControlDesigner)
GetPersistInnerHtml()	Gets the markup to persist for the inner tags of the control. (Inherited from TextControlDesigner)
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. (Inherited from ControlDesigner)
Initialize(IComponent)	Initializes the designer with the specified component. (Inherited from TextControlDesigner)
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. (Inherited from ControlDesigner)
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. (Inherited from ControlDesigner)
InvokeGetInheritanceAttribute(ComponentDesigner)	Gets the InheritanceAttribute of the specified ComponentDesigner. (Inherited from ComponentDesigner)
IsPropertyBound(String)	Obsolete. Retrieves a value indicating whether the specified property on the associated control is data-bound. (Inherited from ControlDesigner)
Localize(IDesignTimeResourceWriter)	Uses the provided resource writer to persist the localizable properties of the associated control to a resource in the design host. (Inherited from ControlDesigner)
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. (Inherited from ControlDesigner)
OnBehaviorAttached()	Called when the control designer is attached to a Behavior object. (Inherited from ControlDesigner)
OnBehaviorDetaching()	Obsolete. Called when a behavior disassociates from the element. (Inherited from HtmlControlDesigner)
OnBindingsCollectionChanged(String)	Obsolete. Called when the data-binding collection changes. (Inherited from ControlDesigner)
OnClick(DesignerRegionMouseEventArgs)	Called by the design host when the user clicks the associated control at design time. (Inherited from ControlDesigner)
OnComponentChanged(Object, ComponentChangedEventArgs)	Called when there is a change to the associated control.
OnComponentChanged(Object, ComponentChangedEventArgs)	Called when the associated control changes. (Inherited from ControlDesigner)
OnComponentChanging(Object, ComponentChangingEventArgs)	Represents the method that will handle the ComponentChanging event for the associated control. (Inherited from ControlDesigner)
OnControlResize()	Obsolete. Called when the associated Web server control has been resized in the design host at design time. (Inherited from ControlDesigner)
OnPaint(PaintEventArgs)	Called when the control designer draws the associated control on the design surface, if the CustomPaint value is `true`. (Inherited from ControlDesigner)
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. (Inherited from ControlDesigner)
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. (Inherited from ControlDesigner)
RegisterClone(Object, Object)	Registers internal data in a cloned control. (Inherited from ControlDesigner)
SetEditableDesignerRegionContent(EditableDesignerRegion, String)	Specifies the content for an editable region of the control at design time. (Inherited from ControlDesigner)
SetRegionContent(EditableDesignerRegion, String)	Specifies the content for an editable region in the design-time view of the control. (Inherited from ControlDesigner)
SetViewFlags(ViewFlags, Boolean)	Assigns the specified bitwise ViewFlags enumeration to the specified flag value. (Inherited from ControlDesigner)
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. (Inherited from ControlDesigner)

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

Jaa