DeclarativeCatalogPart Class

Note: This class is new in the .NET Framework version 2.0.

Enables developers to add a catalog of WebPart or other server controls to a Web page in the declarative, page persistence format. This class cannot be inherited.

Namespace: System.Web.UI.WebControls.WebParts
Assembly: System.Web (in system.web.dll)

'Declaration
Public NotInheritable Class DeclarativeCatalogPart
	Inherits CatalogPart
'Usage
Dim instance As DeclarativeCatalogPart

public final class DeclarativeCatalogPart extends CatalogPart
public final class DeclarativeCatalogPart extends CatalogPart

Just as there are tool-oriented zones in the Web Parts control set (for details, see the ToolZone class overview), there are tool-oriented Part controls, and each of these controls must reside in a certain type of tool zone. Tool-oriented part controls in the Web Parts control set have two distinguishing characteristics:

  • They are helper controls that enable end users to personalize controls on a Web Parts page.

  • They are visible only in certain display modes.

DeclarativeCatalogPart is a part control that must reside in a CatalogZoneBase type of zone, such as the CatalogZone zone provided with the Web Parts control set. The DeclarativeCatalogPart control becomes visible only when a Web page is in catalog display mode.

The DeclarativeCatalogPart control provides a way for developers to add a set of server controls declaratively to a catalog on a Web page. A catalog, in the Web Parts control set, is simply a list of WebPart or other server controls that is visible when a page is in catalog display mode. A user can select controls from the list and add them to the Web page, which effectively gives users the ability to change the set of controls and the functionality on a page.

NoteNote

Users can add multiple instances of the same control in a catalog to a Web page.

An advantage of using a DeclarativeCatalogPart control to create a catalog of server controls is that it does not require any coding. Page developers can work with the control entirely in the declarative (or page persistence) format, hence the name of the control.

The DeclarativeCatalogPart control has a useful property that allows developers to set up a catalog of controls that can be used throughout an entire site. Rather than declare individual server controls within a DeclarativeCatalogPart control, a developer can set the WebPartsListUserControlPath property value to the path of a user control that contains the list of server controls that should be in the catalog. At run time, the server controls referenced in the user control are loaded in the catalog. In this way, multiple pages or sites could reference the same user control to create a catalog. When the user control's list of server controls is updated, it would update all catalogs based on the user control.

The DeclarativeCatalogPart class has a number of public properties that override the inherited properties. Most of these properties are not actually used for rendering the control; they are overridden only so that special code attributes can be set on them to hide them from design tools like Microsoft Visual Studio 2005. You should not use these hidden properties, as they have no effect on rendering. The fact that they are hidden from IntelliSense and the Properties pane in Visual Studio helps developers avoid using them by mistake. All these hidden properties are noted as such in their respective Help topics.

The DeclarativeCatalogPart class also has several methods. The GetAvailableWebPartDescriptions method retrieves a WebPartDescription object for each WebPart control in the catalog, which enables a DeclarativeCatalogPart control to display information about each server control without having to create an instance of it. Another method is the GetWebPart method. This method gets an instance of a particular WebPart control, based on the description passed to the method.

NoteNote

To improve accessibility, the DeclarativeCatalogPart control is rendered within a <fieldset> element. The <fieldset> element groups the related set of controls used for editing in the DeclarativeCatalogPart control, and it facilitates tabbed navigation among those controls for both visual user agents (such as ordinary Web browsers) and speech-oriented user agents (such as screen-reading software).

TopicLocation
How to: Enable Users to Import Web Parts Control SettingsBuilding ASP .NET Web Applications
How to: Set the Display Mode of a Web Parts PageBuilding ASP .NET Web Applications
How to: Provide Optional Web Parts ControlsBuilding ASP .NET Web Applications
How to: Enable Users to Import Web Parts Control SettingsBuilding ASP .NET Web Applications
How to: Set the Display Mode of a Web Parts PageBuilding ASP .NET Web Applications
How to: Provide Optional Web Parts ControlsBuilding ASP .NET Web Applications

The following code example demonstrates how to use the DeclarativeCatalogPart control declaratively on a Web page. The example has four parts:

  • A user control that enables you to change display modes on a Web Parts page.

  • A Web page that contains a CatalogZone control and a DeclarativeCatalogPart control.

  • A source code file that contains two custom WebPart controls.

  • An explanation of how the example works when you load the page in a browser.

The first part of this code example is the user control that enables you to change display modes on the page. For details about display modes and a description of the source code in this control, see Walkthrough: Changing Display Modes on a Web Parts Page.

<%@ control language="vb" classname="DisplayModeMenuVB"%>
<script runat="server">
  ' Use a field to reference the current WebPartManager.
  Dim _manager As WebPartManager

  Sub Page_Init(ByVal sender As Object, ByVal e As EventArgs)
    AddHandler Page.InitComplete, AddressOf InitComplete
  End Sub

  Sub InitComplete(ByVal sender As Object, ByVal e As System.EventArgs)
    _manager = WebPartManager.GetCurrentWebPartManager(Page)
      
    Dim browseModeName As String = WebPartManager.BrowseDisplayMode.Name
      
    ' Fill the dropdown with the names of supported display modes.
    Dim mode As WebPartDisplayMode
    For Each mode In _manager.SupportedDisplayModes
      Dim modeName As String = mode.Name
      ' Make sure a mode is enabled before adding it.
      If mode.IsEnabled(_manager) Then
        Dim item As New ListItem(modeName, modeName)
        DisplayModeDropdown.Items.Add(item)
      End If
    Next mode
      
    ' If shared scope is allowed for this user, display the scope-switching
    ' UI and select the appropriate radio button for the current user scope.
    If _manager.Personalization.CanEnterSharedScope Then
      Panel2.Visible = True
      If _manager.Personalization.Scope = PersonalizationScope.User Then
        RadioButton1.Checked = True
      Else
        RadioButton2.Checked = True
      End If
    End If
   
  End Sub

  ' Change the page to the selected display mode.
  Sub DisplayModeDropdown_SelectedIndexChanged(ByVal sender As Object, _
    ByVal e As EventArgs)
    
    Dim selectedMode As String = DisplayModeDropdown.SelectedValue   
    Dim mode As WebPartDisplayMode = _
      _manager.SupportedDisplayModes(selectedMode)
    If Not (mode Is Nothing) Then
      _manager.DisplayMode = mode
    End If

  End Sub
   
  ' Set the selected item equal to the current display mode.
  Sub Page_PreRender(ByVal sender As Object, ByVal e As EventArgs)
    Dim items As ListItemCollection = DisplayModeDropdown.Items
    Dim selectedIndex As Integer = _
      items.IndexOf(items.FindByText(_manager.DisplayMode.Name))
    DisplayModeDropdown.SelectedIndex = selectedIndex

  End Sub

  ' Reset all of a user's personalization data for the page.
  Protected Sub LinkButton1_Click(ByVal sender As Object, _
    ByVal e As EventArgs)
    
    _manager.Personalization.ResetPersonalizationState()
    
  End Sub

  ' If not in User personalization scope, toggle into it.
  Protected Sub RadioButton1_CheckedChanged(ByVal sender As Object, _
    ByVal e As EventArgs)
    
    If _manager.Personalization.Scope = PersonalizationScope.Shared Then
      _manager.Personalization.ToggleScope()
    End If

  End Sub
   
  ' If not in Shared scope, and if user is allowed, toggle the scope.
  Protected Sub RadioButton2_CheckedChanged(ByVal sender As Object, _
    ByVal e As EventArgs)
    
    If _manager.Personalization.CanEnterSharedScope AndAlso _
      _manager.Personalization.Scope = PersonalizationScope.User Then
      _manager.Personalization.ToggleScope()
    End If

  End Sub

</script>
<div>
  <asp:Panel ID="Panel1" runat="server" 
    Borderwidth="1" 
    Width="230" 
    BackColor="lightgray"
    Font-Names="Verdana, Arial, Sans Serif" >
    <asp:Label ID="Label1" runat="server" 
      Text="&nbsp;Display Mode" 
      Font-Bold="true"
      Font-Size="8"
      Width="120" />
    <asp:DropDownList ID="DisplayModeDropdown" runat="server"  
      AutoPostBack="true" 
      Width="120"
      OnSelectedIndexChanged="DisplayModeDropdown_SelectedIndexChanged" />
    <asp:LinkButton ID="LinkButton1" runat="server"
      Text="Reset User State" 
      ToolTip="Reset the current user's personalization data for the page."
      Font-Size="8" 
      OnClick="LinkButton1_Click" />
    <asp:Panel ID="Panel2" runat="server" 
      GroupingText="Personalization Scope"
      Font-Bold="true"
      Font-Size="8" 
      Visible="false" >
      <asp:RadioButton ID="RadioButton1" runat="server" 
        Text="User" 
        AutoPostBack="true"
        GroupName="Scope" OnCheckedChanged="RadioButton1_CheckedChanged" />
      <asp:RadioButton ID="RadioButton2" runat="server" 
        Text="Shared" 
        AutoPostBack="true"
        GroupName="Scope" 
        OnCheckedChanged="RadioButton2_CheckedChanged" />
    </asp:Panel>
  </asp:Panel>
</div>

The second part of the code example is the Web page. At the top of the page are two Register directives, one for the user control and one for the compiled component that contains the two custom WebPart controls. Notice that the page has a declarative reference to the DeclarativeCatalogPart control, nested within the proper hierarchy of declarative elements as described in the Remarks section of this topic. The <asp:declarativecatalogpart> element contains a <webpartstemplate> element, which in turn contains references for a standard ASP.NET Calendar control and the two custom WebPart controls; these are the controls that users can select from the catalog. The page also contains editing capability, with a PropertyGridEditorPart control declared on the page. This control enables users to edit certain properties on the custom WebPart controls after they have been added to the page, and after the user has switched the page to edit mode.

<%@ page language="VB" %>
<%@ register TagPrefix="uc1" 
  TagName="DisplayModeMenuVB" 
  Src="DisplayModeMenuVB.ascx" %>
<%@ register tagprefix="aspSample" 
  Namespace="Samples.AspNet.VB.Controls" 
  Assembly="UserInfoWebPartVB" %>

<html>
  <head runat="server">
    <title>
      DeclarativeCatalogPart Control
    </title>
  </head>
  <body>
    <form id="form1" runat="server">
      <asp:webpartmanager id="WebPartManager1" runat="server"  />
      <uc1:DisplayModeMenuVB ID="DisplayModeMenu1" runat="server" />
      <asp:webpartzone id="zone1" runat="server" >
        <PartTitleStyle BorderWidth=1 
          Font-Names="Verdana, Arial"
          Font-Size="110%"
          BackColor="LightBlue" />
        <zonetemplate>
          <asp:BulletedList ID="BulletedList1" 
            Runat="server"
            DisplayMode="HyperLink"
            Title="Favorites">
            <asp:ListItem Value="http://msdn.microsoft.com">
              MSDN
            </asp:ListItem>
            <asp:ListItem Value="http://www.asp.net">
              ASP.NET
            </asp:ListItem>
            <asp:ListItem Value="http://www.msn.com">
              MSN
            </asp:ListItem>
          </asp:BulletedList>
        </zonetemplate>
      </asp:webpartzone> 
      <asp:CatalogZone ID="CatalogZone1" runat="server">
        <ZoneTemplate>
          <asp:DeclarativeCatalogPart ID="DeclarativeCatalogPart1"  
            runat="server" 
            Title="Web Parts Catalog"
            ChromeType="TitleOnly" 
            Description="Contains a user control with Web Parts and 
              an ASP.NET Calendar control.">
            <WebPartsTemplate>
              <asp:Calendar ID="Calendar1" runat="server" 
                Title="My Calendar" 
                Description="ASP.NET Calendar control used as a personal calendar." />
              <aspSample:UserInfoWebPart 
                runat="server"   
                id="userinfo1" 
                title = "User Information WebPart"
                Description ="Contains custom, editable user information 
                  for display on a page." />
              <aspSample:TextDisplayWebPart 
                runat="server"   
                id="TextDisplayWebPart1" 
                title = "Text Display WebPart" 
                Description="Contains a label that users can dynamically update." />
            </WebPartsTemplate>              
          </asp:DeclarativeCatalogPart>
        </ZoneTemplate>
      </asp:CatalogZone>
      <asp:EditorZone ID="EditorZone1" runat="server">
      <ZoneTemplate>
        <asp:PropertyGridEditorPart ID="PropertyGridEditorPart1" runat="server" />
      </ZoneTemplate>
      </asp:EditorZone> 
    </form>
  </body>
</html>

The third part of the code example is the source code for the two WebPart controls. Notice that some properties on these controls are marked with the WebBrowsable attribute. This enables the PropertyGridEditorPart control to dynamically generate the user interface (UI) for a user to edit those properties when the controls are in edit mode. The properties are also marked with a WebDisplayName attribute, to specify the text of the label that appears next to each control in the editing UI.

For the code example to run, you must compile this source code. You can compile it explicitly and put the resulting assembly in your Web site's Bin folder or the global assembly cache. Alternatively, you can put the source code in your site's App_Code folder, where it will be dynamically compiled at run time. For a walkthrough that demonstrates both methods of compiling, see Walkthrough: Developing and Using a Custom Server Control.

Imports System
Imports System.Collections
Imports System.ComponentModel
Imports System.Drawing
Imports System.Security.Permissions
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Web.UI.WebControls.WebParts

Namespace Samples.AspNet.VB.Controls

  <AspNetHostingPermission(SecurityAction.Demand, _
    Level:=AspNetHostingPermissionLevel.Minimal)> _
  <AspNetHostingPermission(SecurityAction.InheritanceDemand, _
    Level:=AspNetHostingPermissionLevel.Minimal)> _
  Public Class UserInfoWebPart
    Inherits WebPart
    Private server As HttpServerUtility = HttpContext.Current.Server
    Private _userNickName As String = "Add a nickname."
    Private _userPetName As String = "Add a pet's name."
    Private _userSpecialDate As DateTime = DateTime.Now
    Private _userIsCurrent As [Boolean] = True
    Private _userJobType As JobTypeName = JobTypeName.Unselected

    Public Enum JobTypeName
      Unselected = 0
      Support = 1
      Service = 2
      Professional = 3
      Technical = 4
      Manager = 5
      Executive = 6
    End Enum

    Private NickNameLabel As Label
    Private PetNameLabel As Label
    Private SpecialDateLabel As Label
    Private IsCurrentCheckBox As CheckBox
    Private JobTypeLabel As Label

    ' Add the Personalizable and WebBrowsable attributes to the  
    ' public properties, so that users can save property values  
    ' and edit them with a PropertyGridEditorPart control.

    <Personalizable(), WebBrowsable(), WebDisplayName("Nickname")> _
    Public Property NickName() As String
      Get
        Dim o As Object = ViewState("NickName")
        If Not (o Is Nothing) Then
          Return CStr(o)
        Else
          Return _userNickName
        End If
      End Get
      Set(ByVal value As String)
        _userNickName = server.HtmlEncode(value)
      End Set
    End Property

    <Personalizable(), WebBrowsable(), WebDisplayName("Pet Name")> _
    Public Property PetName() As String
      Get
        Dim o As Object = ViewState("PetName")
        If Not (o Is Nothing) Then
          Return CStr(o)
        Else
          Return _userPetName
        End If
      End Get
      Set(ByVal value As String)
        _userPetName = server.HtmlEncode(value)
      End Set
    End Property

    <Personalizable(), WebBrowsable(), WebDisplayName("Special Day")> _
    Public Property SpecialDay() As DateTime
      Get
        Dim o As Object = ViewState("SpecialDay")
        If Not (o Is Nothing) Then
          Return CType(o, DateTime)
        Else
          Return _userSpecialDate
        End If
      End Get

      Set(ByVal value As DateTime)
        _userSpecialDate = value
      End Set
    End Property

    <Personalizable(), WebBrowsable(), WebDisplayName("Job Type")> _
    Public Property UserJobType() As JobTypeName
      Get
        Dim o As Object = ViewState("UserJobType")
        If Not (o Is Nothing) Then
          Return CType(o, JobTypeName)
        Else
          Return _userJobType
        End If
      End Get
      Set(ByVal value As JobTypeName)
        _userJobType = CType(value, JobTypeName)
      End Set
    End Property

    <Personalizable(), WebBrowsable(), WebDisplayName("Is Current")> _
    Public Property IsCurrent() As [Boolean]
      Get
        Dim o As Object = ViewState("IsCurrent")
        If Not (o Is Nothing) Then
          Return CType(o, [Boolean])
        Else
          Return _userIsCurrent
        End If
      End Get
      Set(ByVal value As [Boolean])
        _userIsCurrent = value
      End Set
    End Property

    Protected Overrides Sub CreateChildControls()
      Controls.Clear()

      NickNameLabel = New Label()
      NickNameLabel.Text = Me.NickName
      SetControlAttributes(NickNameLabel)

      PetNameLabel = New Label()
      PetNameLabel.Text = Me.PetName
      SetControlAttributes(PetNameLabel)

      SpecialDateLabel = New Label()
      SpecialDateLabel.Text = Me.SpecialDay.ToShortDateString()
      SetControlAttributes(SpecialDateLabel)

      IsCurrentCheckBox = New CheckBox()
      IsCurrentCheckBox.Checked = Me.IsCurrent
      SetControlAttributes(IsCurrentCheckBox)

      JobTypeLabel = New Label()
      JobTypeLabel.Text = Me.UserJobType.ToString()
      SetControlAttributes(JobTypeLabel)

      ChildControlsCreated = True

    End Sub

    Private Sub SetControlAttributes(ByVal ctl As WebControl)
      ctl.BackColor = Color.White
      ctl.BorderWidth = 1
      ctl.Width = 200
      Me.Controls.Add(ctl)
    End Sub

    Protected Overrides Sub RenderContents(ByVal writer As HtmlTextWriter)
      writer.Write("Nickname:")
      writer.WriteBreak()
      NickNameLabel.RenderControl(writer)
      writer.WriteBreak()
      writer.Write("Pet Name:")
      writer.WriteBreak()
      PetNameLabel.RenderControl(writer)
      writer.WriteBreak()
      writer.Write("Special Date:")
      writer.WriteBreak()
      SpecialDateLabel.RenderControl(writer)
      writer.WriteBreak()
      writer.Write("Job Type:")
      writer.WriteBreak()
      JobTypeLabel.RenderControl(writer)
      writer.WriteBreak()
      writer.Write("Current:")
      writer.WriteBreak()
      IsCurrentCheckBox.RenderControl(writer)

    End Sub

  End Class


  <AspNetHostingPermission(SecurityAction.Demand, _
    Level:=AspNetHostingPermissionLevel.Minimal)> _
  <AspNetHostingPermission(SecurityAction.InheritanceDemand, _
    Level:=AspNetHostingPermissionLevel.Minimal)> _
  Public Class TextDisplayWebPart
    Inherits WebPart
    Private _contentText As String = Nothing
    Private _fontStyle As String = Nothing
    Private input As TextBox
    Private DisplayContent As Label
    Private lineBreak As Literal

    <Personalizable(), WebBrowsable()> _
    Public Property ContentText() As String
      Get
        Return _contentText
      End Get
      Set(ByVal value As String)
        _contentText = value
      End Set
    End Property

    Protected Overrides Sub CreateChildControls()
      Controls.Clear()
      DisplayContent = New Label()
      DisplayContent.BackColor = Color.LightBlue
      DisplayContent.Text = Me.ContentText
      Me.Controls.Add(DisplayContent)

      lineBreak = New Literal()
      lineBreak.Text = "<br />"
      Controls.Add(lineBreak)

      input = New TextBox()
      Me.Controls.Add(input)
      Dim update As New Button()
      update.Text = "Set Label Content"
      AddHandler update.Click, AddressOf Me.submit_Click
      Me.Controls.Add(update)

    End Sub

    Private Sub submit_Click(ByVal sender As Object, _
                             ByVal e As EventArgs)
      ' Update the label string.
      If input.Text <> String.Empty Then
        _contentText = input.Text + "<br />"
        input.Text = String.Empty
        DisplayContent.Text = Me.ContentText
      End If

    End Sub

  End Class

End Namespace

When you load the page in a browser, select Catalog Mode in the Display Mode drop-down list control to switch to catalog mode. In catalog mode, you can see the controls that are available to be added to the page. Add all three controls, and then use the Display Mode drop-down list to return the page to browse mode. The three controls appear on the page. If you use the Display Mode drop-down list and switch the page to edit mode, you can click the verbs menu (the downward arrow) in the title bar of the User Information WebPart control, and click Edit to edit the control. When the editing UI is visible, you can see the PropertyGridEditorPart control. Notice that a control is rendered for each of the properties of the UserInfoWebPart class that was marked with the WebBrowsable attribute. If you make some changes in the editing UI and click the Apply button, you can use the Display Mode drop-down list to return the page to browse mode and see the full effect of the editing changes.

  • AspNetHostingPermission  for operating in a hosted environment. Demand value: LinkDemand; Permission value: Minimal.
  • AspNetHostingPermission  for operating in a hosted environment. Demand value: InheritanceDemand; Permission value: Minimal.

System.Object
   System.Web.UI.Control
     System.Web.UI.WebControls.WebControl
       System.Web.UI.WebControls.Panel
         System.Web.UI.WebControls.WebParts.Part
           System.Web.UI.WebControls.WebParts.CatalogPart
            System.Web.UI.WebControls.WebParts.DeclarativeCatalogPart

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

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

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0

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