WebPartDesigner Class
Definition
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 visual support for WebPart controls.
public ref class WebPartDesigner : System::Web::UI::Design::WebControls::WebParts::PartDesignerpublic class WebPartDesigner : System.Web.UI.Design.WebControls.WebParts.PartDesignertype WebPartDesigner = class
inherit PartDesignerPublic Class WebPartDesigner
Inherits PartDesigner- Inheritance
Examples
The following code example shows the interaction between a WebPart control and its associated WebPartDesigner. The WebPart control contains a Calendar control from which the end user selects their birthday, a Button control to submit the selection, and a Label control to display a message on the user's birthday. The WebPartDesigner verifies that the associated control is of the expected type and then customizes the design-time rendering of said control. Note that the visual customizations of the designer are visible only at design time, whereas those of the associated control are visible at both run time and design time.
All the methods overridden in this example derive from the ControlDesigner base class. For other available members and their use, see System.Web.UI.Design.ControlDesigner.
using System;
using System.Security.Permissions;
using System.Web;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.Design.WebControls.WebParts;
using System.ComponentModel;
/// <summary>
/// BirthdayPart demonstrates some of the most
/// common overrides of members of the WebPart
/// class. BirthdayPartDesigner shows how to
/// customize the rendering of a custom WebPart
/// control.
/// </summary>
namespace Samples.AspNet.CS.Controls
{
[AspNetHostingPermission(SecurityAction.Demand,
Level=AspNetHostingPermissionLevel.Minimal)]
[AspNetHostingPermission(SecurityAction.InheritanceDemand,
Level=AspNetHostingPermissionLevel.Minimal)]
[Designer(typeof(BirthdayPartDesigner))]
public class BirthdayPart : WebPart
{
private DateTime birthDate;
Calendar input;
Label displayContent;
public BirthdayPart()
{
this.AllowClose = false;
this.Title = "Enter your birthday";
}
[
Personalizable(PersonalizationScope.User, true),
WebBrowsable()
]
public DateTime BirthDate
{
get { return birthDate; }
set { birthDate = value; }
}
// Set the appearance of the control at run time.
protected override void CreateChildControls()
{
Controls.Clear();
input = new Calendar();
this.Controls.Add(input);
Button update = new Button();
update.Text = "Submit";
update.Click += new EventHandler(this.submit_Click);
this.Controls.Add(update);
displayContent = new Label();
displayContent.BackColor =
System.Drawing.Color.LightBlue;
Literal br = new Literal();
br.Text = "<br />";
if ((this.birthDate.Day == DateTime.Now.Day)
&& (this.birthDate.Month == DateTime.Now.Month))
{
displayContent.Text = "Happy Birthday!";
this.Controls.Add(br);
this.Controls.Add(displayContent);
}
}
private void submit_Click(object sender, EventArgs e)
{
this.birthDate = input.SelectedDate;
}
}
public class BirthdayPartDesigner : WebPartDesigner
{
public override void Initialize(IComponent component)
{
// Verify that the associated control is a BirthdayPart.
if (!typeof(BirthdayPart).IsInstanceOfType(component))
{
throw new ArgumentException("The specified control is not of type 'BirthdayPart'", "component");
}
base.Initialize(component);
}
// Here is where you make customizations
// to design time appearance that will not
// be visible to the end user.
public override string GetDesignTimeHtml()
{
string designTimeHtml = null;
try
{
designTimeHtml = base.GetDesignTimeHtml();
string s = "<hr /><hr />I just added these lines to the"
+ " bottom of the control.<hr /><hr /></div>";
designTimeHtml = designTimeHtml.Replace("</div>", s);
}
catch (Exception ex)
{
designTimeHtml = GetErrorDesignTimeHtml(ex);
}
finally
{
// undo any changes in the try block
}
if ((designTimeHtml == null) || (designTimeHtml.Length == 0))
{
designTimeHtml = GetEmptyDesignTimeHtml();
}
return designTimeHtml;
}
// This method normally returns a blank string.
// Override to return a meaningful message.
protected override string GetEmptyDesignTimeHtml()
{
return CreatePlaceHolderDesignTimeHtml(
"<hr />If the page developer forgot to fill in a " +
"required property you could tell them here.<hr />");
}
// Add specific text to the generic error message.
protected override string GetErrorDesignTimeHtml(Exception e)
{
string s = "<hr />The control failed to render.";
return(s + e.Message + "<hr />");
}
}
}
Imports System.Security.Permissions
Imports System.Web
Imports System.Web.UI.WebControls
Imports System.Web.UI.WebControls.WebParts
Imports System.Web.UI.Design.WebControls.WebParts
Imports System.ComponentModel
' BirthdayPart demonstrates some of the most
' common overrides of members of the WebPart
' class. BirthdayPartDesigner shows how to
' customize the rendering of a custom WebPart
' control.
Namespace Samples.AspNet.VB.Controls
<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
<AspNetHostingPermission(SecurityAction.InheritanceDemand, Level:=AspNetHostingPermissionLevel.Minimal)> _
<Designer(GetType(BirthdayPartDesigner))> _
Public Class BirthdayPart
Inherits WebPart
Private m_birthDate As DateTime
Private input As Calendar
Private displayContent As Label
Public Sub New()
Me.AllowClose = False
Me.Title = "Enter your birthday"
End Sub
<Personalizable(PersonalizationScope.User, True), WebBrowsable()> _
Public Property BirthDate() As DateTime
Get
Return m_birthDate
End Get
Set(value As DateTime)
m_birthDate = value
End Set
End Property
' Set the appearance of the control at run time.
Protected Overrides Sub CreateChildControls()
Controls.Clear()
input = New Calendar()
Me.Controls.Add(input)
Dim update As New Button()
update.Text = "Submit"
AddHandler update.Click, New EventHandler(AddressOf Me.submit_Click)
Me.Controls.Add(update)
displayContent = New Label()
displayContent.BackColor = System.Drawing.Color.LightBlue
Dim br As New Literal()
br.Text = "<br />"
If (Me.m_birthDate.Day = DateTime.Now.Day) AndAlso (Me.m_birthDate.Month = DateTime.Now.Month) Then
displayContent.Text = "Happy Birthday!"
Me.Controls.Add(br)
Me.Controls.Add(displayContent)
End If
End Sub
Private Sub submit_Click(sender As Object, e As EventArgs)
Me.m_birthDate = input.SelectedDate
End Sub
End Class
Public Class BirthdayPartDesigner
Inherits WebPartDesigner
Public Overrides Sub Initialize(component As IComponent)
' Verify that the associated control is a BirthdayPart.
If Not GetType(BirthdayPart).IsInstanceOfType(component) Then
Throw New ArgumentException("The specified control is not of type 'BirthdayPart'", "component")
End If
MyBase.Initialize(component)
End Sub
' Here is where you make customizations
' to design time appearance that will not
' be visible to the end user.
Public Overrides Function GetDesignTimeHtml() As String
Dim designTimeHtml As String = Nothing
Try
designTimeHtml = MyBase.GetDesignTimeHtml()
Dim s As String = "<hr /><hr />I just added these lines to the" & " bottom of the control.<hr /><hr /></div>"
designTimeHtml = designTimeHtml.Replace("</div>", s)
Catch ex As Exception
designTimeHtml = GetErrorDesignTimeHtml(ex)
' undo any changes in the try block
Finally
End Try
If (designTimeHtml Is Nothing) OrElse (designTimeHtml.Length = 0) Then
designTimeHtml = GetEmptyDesignTimeHtml()
End If
Return designTimeHtml
End Function
' This method normally returns a blank string.
' Override to return a meaningful message.
Protected Overrides Function GetEmptyDesignTimeHtml() As String
Return CreatePlaceHolderDesignTimeHtml("<hr />If the page developer forgot to fill in a " & "required property you could tell them here.<hr />")
End Function
' Add specific text to the generic error message.
Protected Overrides Function GetErrorDesignTimeHtml(e As Exception) As String
Dim s As String = "<hr />The control failed to render."
Return (s & e.Message & "<hr />")
End Function
End Class
End Namespace
Remarks
The WebPartDesigner class provides the visual representation for WebPart controls at design time. It is derived from the PartDesigner class and adds validation to verify that the associated control is a WebPart control or derived type.
WebPartDesigner inherits a UsePreviewControl property from its parent that is always set to true. This causes the visual design environment to generate a View control to hold a temporary copy of the WebPart on the design surface; this copy is then persisted into markup. If you override the UsePreviewControl property to return false, the visual design environment generates markup directly from the actual WebPart control.
Web Parts designers generally act much like regular control designers; the principal methods for setting design-time appearance derive from the ControlDesigner class. Specifically, you can override the GetDesignTimeHtml method to change the design-time markup associated with the control. You can likewise override the GetErrorDesignTimeHtml and GetEmptyDesignTimeHtml methods to handle errors and empty strings (""), respectively.
Constructors
| WebPartDesigner() |
Initializes a new instance of the WebPartDesigner 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 designer should use a temporary copy rather than the actual control associated with the designer to generate the design-time markup. (Inherited from PartDesigner) |
| 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 |
| 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, 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 HTML that is used to represent the control at design time. (Inherited from CompositeControlDesigner) |
| 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() |
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) |
Binds the designer to a control and validates that the control is a WebPart 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 |
| 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) |
