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LoginDesigner Class

Definition

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

public ref class LoginDesigner : System::Web::UI::Design::WebControls::CompositeControlDesigner
public class LoginDesigner : System.Web.UI.Design.WebControls.CompositeControlDesigner
type LoginDesigner = class
    inherit CompositeControlDesigner
Public Class LoginDesigner
Inherits CompositeControlDesigner
Inheritance

Examples

The following code example shows how to extend the LoginDesigner class to change the appearance of controls that are derived from the Login control at design time.

The example derives the MyLogin control from the Login. The MyLogin is a copy of the Login control. The example also derives the MyLoginDesigner class from the LoginDesigner and applies a DesignerAttribute attribute for the MyLoginDesigner on the MyLogin control.

The MyLoginDesigner overrides the PreFilterProperties method to make the NamingContainer property visible in the Properties grid at design time. It overrides the GetDesignTimeHtml method to draw a blue, dashed border around the control to make its extent more visible, if the BorderStyle property of the MyLogin control is the NotSet or None value. It overrides the GetErrorDesignTimeHtml method to generate the markup for a placeholder that includes the error message rendered in red, bold text.

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

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

    // Override members of the LoginDesigner.
    [ReflectionPermission(SecurityAction.Demand, Flags=ReflectionPermissionFlag.MemberAccess)]
    public class MyLoginDesigner : LoginDesigner
    {
        // Generate the design-time markup for the control when an error occurs.
        protected override string GetErrorDesignTimeHtml(Exception e) 
        {
            // Write the error message text in red, bold.
            string errorRendering =
                "<span style=\"font-weight:bold; color:Red; \">" +
                e.Message + "</span>";

            return CreatePlaceHolderDesignTimeHtml(errorRendering);
        } // GetErrorDesignTimeHtml

        // Shadow the control properties with design-time properties.
        protected override void PreFilterProperties(IDictionary properties)
        {
            // Call the base method first.
            base.PreFilterProperties(properties);

            // Make the NamingContainer visible in the Properties grid.
            PropertyDescriptor selectProp = 
                (PropertyDescriptor)properties["NamingContainer"];
            properties["NamingContainer"] =
                TypeDescriptor.CreateProperty(selectProp.ComponentType, 
                    selectProp, BrowsableAttribute.Yes);
        } // PreFilterProperties

        // 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 blue dashed line. 
            MyLogin myLoginCtl = (MyLogin)ViewControl;
            string markup = null;

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

                // Set the design time properties and catch any exceptions.
                try
                {
                    myLoginCtl.BorderStyle = BorderStyle.Dashed;
                    myLoginCtl.BorderColor = Color.Blue;

                    // Call the base method to generate the markup.
                    markup = base.GetDesignTimeHtml();
                }
                catch (Exception ex)
                {
                    markup = GetErrorDesignTimeHtml(ex);
                }
                finally
                {
                    // It is not necessary to restore the border properties 
                    // to their original values because the ViewControl 
                    // was used to reference the associated control and the 
                    // UsePreviewControl was not overridden.  

                    // myLoginCtl.BorderStyle = oldBorderStyle;
                    // myLoginCtl.BorderColor = oldBorderColor;
                }
            }
            else
            {
                // Call the base method to generate the markup.
                markup = base.GetDesignTimeHtml();
            }

            return markup;
        } // GetDesignTimeHtml
    } // MyLoginDesigner
} // Examples.CS.WebControls.Design
Imports System.Web
Imports System.Drawing
Imports System.Web.UI.WebControls
Imports System.Web.UI.Design.WebControls
Imports System.Collections
Imports System.ComponentModel
Imports System.Security.Permissions

Namespace Examples.VB.WebControls.Design

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

    ' Override members of the LoginDesigner.
    <ReflectionPermission(SecurityAction.Demand, Flags:=ReflectionPermissionFlag.MemberAccess)> _
    Public Class MyLoginDesigner
        Inherits LoginDesigner

        ' Generate the design-time markup for the control when an error occurs.
        Protected Overrides Function GetErrorDesignTimeHtml( _
            ByVal ex As Exception) As String

            ' Write the error message text in red, bold.
            Dim errorRendering As String = _
                "<span style=""font-weight:bold; color:Red; "">" & _
                ex.Message & "</span>"

            Return CreatePlaceHolderDesignTimeHtml(errorRendering)

        End Function ' GetErrorDesignTimeHtml

        ' Shadow the control properties with design-time properties.
        Protected Overrides Sub PreFilterProperties( _
            ByVal properties As IDictionary)

            ' Call the base method first.
            MyBase.PreFilterProperties(properties)

            ' Make the NamingContainer visible in the Properties grid.
            Dim selectProp As PropertyDescriptor = _
                CType(properties("NamingContainer"), PropertyDescriptor)
            properties("NamingContainer") = _
                TypeDescriptor.CreateProperty(selectProp.ComponentType, _
                    selectProp, BrowsableAttribute.Yes)
        End Sub

        ' 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 blue dashed line. 
            Dim myLoginCtl As MyLogin = CType(ViewControl, MyLogin)
            Dim markup As String = Nothing

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

                Dim oldBorderStyle As BorderStyle = myLoginCtl.BorderStyle
                Dim oldBorderColor As Color = myLoginCtl.BorderColor

                ' Set the design time properties and catch any exceptions.
                Try
                    myLoginCtl.BorderStyle = BorderStyle.Dashed
                    myLoginCtl.BorderColor = Color.Blue

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

                Catch ex As Exception
                    markup = GetErrorDesignTimeHtml(ex)

                Finally
                    ' It is not necessary to restore the border properties 
                    ' to their original values because the ViewControl 
                    ' was used to reference the associated control and the 
                    ' UsePreviewControl was not overridden.  

                    ' myLoginCtl.BorderStyle = oldBorderStyle
                    ' myLoginCtl.BorderColor = oldBorderColor
                End Try

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

            Return markup

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

Remarks

The Login control displays a user interface that allows a user to log on to the host Web site.

In a visual designer, when you switch from Source to Design view, the markup source code that describes the Login 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 LoginDesigner class provides design-time support for the Login control.

The LoginDesigner class properties provide the following functionality:

  • The ActionLists property returns a DesignerActionListCollection object, which typically contains an object that is derived from the DesignerActionList class for each level in the inheritance tree of the designer.

  • The AutoFormats property returns a collection of formatting schemes for display in the Auto Format dialog box.

  • The TemplateGroups property returns a collection of template groups for the fields of the associated Login control and the top-level Login template.

  • The UsePreviewControl property always returns true, indicating that the designer creates a temporary copy of the associated Login to generate the design-time markup.

The LoginDesigner class methods provide the following functionality:

Constructors

LoginDesigner()

Initializes a new instance of the LoginDesigner class.

Properties

ActionLists

Gets the designer action-list collection for this designer.

AllowResize

Gets or sets a value that specifies whether the LoginDesigner control allows resizing.

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 formatting schemes to display in the Auto Format dialog box.

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)
RenderOuterTable

Gets or sets a value that specifies whether the LoginDesigner control uses an outer table container to apply inline CSS style rules.

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 for the fields of the associated control.

UsePreviewControl

Gets a value indicating whether the designer should use a temporary copy rather than the actual control associated with the designer to generate the design-time 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.

(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

CreateChildControls()

Creates the child controls of this CompositeControl control.

(Inherited from CompositeControlDesigner)
CreateErrorDesignTimeHtml(String)

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

(Inherited from ControlDesigner)
CreateErrorDesignTimeHtml(String, Exception)

Creates the HTML markup to display a specified exception 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 HTML that is used to represent the control at design time.

(Inherited from CompositeControlDesigner)
GetDesignTimeHtml(DesignerRegionCollection)

Gets the markup that is used to render the associated control at design time and populates a collection of designer regions.

GetEditableDesignerRegionContent(EditableDesignerRegion)

Returns a serialized copy of the template that is used to render the associated control at design time.

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)

Provides the markup that is used to render the associated control at design time when an error has occurred.

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()
Obsolete.

Retrieves the persistable inner HTML markup of the control.

(Inherited from ControlDesigner)
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)

Prepares the designer to view, edit, and design the associated control.

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 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)

Used by the designer to remove properties from or add additional properties to the display in the Properties grid or to shadow properties of 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.

(Inherited from ControlDesigner)
RegisterClone(Object, Object)

Registers internal data in a cloned control.

(Inherited from ControlDesigner)
SetEditableDesignerRegionContent(EditableDesignerRegion, String)

Sets a region of the associated control from a serialized copy of a control template.

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

See also