PageCatalogPart.GetAvailableWebPartDescriptions Metodo

Definizione

Spazio dei nomi:

System.Web.UI.WebControls.WebParts

Assembly:

System.Web.dll

Restituisce un insieme di descrizioni dei controlli WebPart disponibili in un catalogo.

public:
 override System::Web::UI::WebControls::WebParts::WebPartDescriptionCollection ^ GetAvailableWebPartDescriptions();

public override System.Web.UI.WebControls.WebParts.WebPartDescriptionCollection GetAvailableWebPartDescriptions ();

override this.GetAvailableWebPartDescriptions : unit -> System.Web.UI.WebControls.WebParts.WebPartDescriptionCollection

Public Overrides Function GetAvailableWebPartDescriptions () As WebPartDescriptionCollection

Restituisce

WebPartDescriptionCollection

Oggetto WebPartDescriptionCollection che contiene un oggetto WebPartDescription per ogni controllo WebPart chiuso in un catalogo di pagina.

Esempio

Nell'esempio di codice riportato di seguito viene illustrato come utilizzare il metodo GetAvailableWebPartDescriptions. In questo esempio sono presenti quattro parti:

• Controllo utente che consente di modificare le modalità di visualizzazione in una pagina web part.

• File di codice sorgente che contiene due controlli personalizzati WebPart .

• Pagina Web contenente un CatalogZone controllo e un PageCatalogPart controllo che fa riferimento a diversi controlli server. La pagina contiene anche il codice di gestione degli eventi che chiama il GetAvailableWebPartDescriptions metodo .

• Spiegazione del funzionamento dell'esempio quando si carica la pagina in un browser.

La prima parte di questo esempio di codice è il controllo utente che consente agli utenti di modificare le modalità di visualizzazione in una pagina Web. Per informazioni dettagliate sulle modalità di visualizzazione e una descrizione del codice sorgente in questo controllo, vedere Procedura dettagliata: Modifica delle modalità di visualizzazione in una pagina Web part.

<%@ control language="C#" classname="DisplayModeMenuCS"%>
<script runat="server">
  
 // Use a field to reference the current WebPartManager.
  WebPartManager _manager;

  void Page_Init(object sender, EventArgs e)
  {
    Page.InitComplete += new EventHandler(InitComplete);
    
  }  

  void InitComplete(object sender, System.EventArgs e)
  {
    _manager = WebPartManager.GetCurrentWebPartManager(Page);

    String browseModeName = WebPartManager.BrowseDisplayMode.Name;

    // Fill the dropdown with the names of supported display modes.
    foreach (WebPartDisplayMode mode in _manager.SupportedDisplayModes)
    {
      String modeName = mode.Name;
      // Make sure a mode is enabled before adding it.
      if (mode.IsEnabled(_manager))
      {
        ListItem item = new ListItem(modeName, modeName);
        DisplayModeDropdown.Items.Add(item);
      }
    }

    // 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)
    {
      Panel2.Visible = true;
      if (_manager.Personalization.Scope == PersonalizationScope.User)
        RadioButton1.Checked = true;
      else
        RadioButton2.Checked = true;
    }
    
  }
 
  // Change the page to the selected display mode.
  void DisplayModeDropdown_SelectedIndexChanged(object sender, EventArgs e)
  {
    String selectedMode = DisplayModeDropdown.SelectedValue;

    WebPartDisplayMode mode = _manager.SupportedDisplayModes[selectedMode];
    if (mode != null)
      _manager.DisplayMode = mode;
  }

  // Set the selected item equal to the current display mode.
  void Page_PreRender(object sender, EventArgs e)
  {
    ListItemCollection items = DisplayModeDropdown.Items;
    int selectedIndex = 
      items.IndexOf(items.FindByText(_manager.DisplayMode.Name));
    DisplayModeDropdown.SelectedIndex = selectedIndex;
  }

  // Reset all of a user's personalization data for the page.
  protected void LinkButton1_Click(object sender, EventArgs e)
  {
    _manager.Personalization.ResetPersonalizationState();
  }

  // If not in User personalization scope, toggle into it.
  protected void RadioButton1_CheckedChanged(object sender, EventArgs e)
  {
    if (_manager.Personalization.Scope == PersonalizationScope.Shared)
      _manager.Personalization.ToggleScope();
  }

  // If not in Shared scope, and if user is allowed, toggle the scope.
  protected void RadioButton2_CheckedChanged(object sender, EventArgs e)
  {
    if (_manager.Personalization.CanEnterSharedScope && 
        _manager.Personalization.Scope == PersonalizationScope.User)
      _manager.Personalization.ToggleScope();
  }
</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=" Display Mode" 
      Font-Bold="true"
      Font-Size="8"
      Width="120" 
      AssociatedControlID="DisplayModeDropdown"/>
    <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>

<%@ 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=" Display Mode" 
      Font-Bold="true"
      Font-Size="8"
      Width="120" AssociatedControlID="DisplayModeDropDown"/>
    <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>

La seconda parte dell'esempio di codice è il codice sorgente per i due controlli personalizzati WebPart . Per eseguire l'esempio di codice, è necessario compilare questo codice sorgente. È possibile compilarlo in modo esplicito e inserire l'assembly risultante nella cartella Bin del sito Web o nella Global Assembly Cache. In alternativa, è possibile inserire il codice sorgente nella cartella App_Code del sito, in cui verrà compilato in modo dinamico in fase di esecuzione. Per una procedura dettagliata che illustra entrambi i metodi di compilazione, vedere Procedura dettagliata: Sviluppo e uso di un controllo server Web personalizzato.

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

namespace Samples.AspNet.CS.Controls
{
  [AspNetHostingPermission(SecurityAction.Demand,
    Level = AspNetHostingPermissionLevel.Minimal)]
  [AspNetHostingPermission(SecurityAction.InheritanceDemand,
    Level = AspNetHostingPermissionLevel.Minimal)]
  public class UserInfoWebPart : WebPart
  {
    HttpServerUtility server = HttpContext.Current.Server;
    private String _userNickName = "Add a nickname.";
    private String _userPetName = "Add a pet's name.";
    private DateTime _userSpecialDate = DateTime.Now;
    private Boolean _userIsCurrent = true;
    private JobTypeName _userJobType = JobTypeName.Unselected;
    public enum JobTypeName
    {
      Unselected = 0,
      Support = 1,
      Service = 2,
      Professional = 3, 
      Technical = 4,
      Manager = 5,
      Executive = 6
    }
    Label NickNameLabel;
    Label PetNameLabel;
    Label SpecialDateLabel;
    CheckBox IsCurrentCheckBox;
    Label JobTypeLabel;

    // 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 String NickName
    {
      get 
      { 
        object o = ViewState["NickName"];
        if (o != null)
          return (string)o;
        else
          return _userNickName;        
      } 

      set { _userNickName = server.HtmlEncode(value); }
    }

    [Personalizable(), WebBrowsable, WebDisplayName("Pet Name")]
    public String PetName
    {
      get 
      { 
        object o = ViewState["PetName"];
        if (o != null)
          return (string)o;
        else
          return _userPetName;        
      }

      set { _userPetName = server.HtmlEncode(value); }
    }

    [Personalizable(), WebBrowsable(), WebDisplayName("Special Day")]
    public DateTime SpecialDay
    {
      get
      {
        object o = ViewState["SpecialDay"];
        if (o != null)
          return (DateTime)o;
        else
          return _userSpecialDate;
      }

      set { _userSpecialDate = value; }
    }

    [Personalizable(), WebBrowsable(), WebDisplayName("Job Type")]
    public JobTypeName UserJobType
    {
      get
      {
        object o = ViewState["UserJobType"];
        if (o != null)
          return (JobTypeName)o;
        else
          return _userJobType;
      }

      set { _userJobType = (JobTypeName)value; }
    }

    [Personalizable(), WebBrowsable(), WebDisplayName("Is Current")]
    public Boolean IsCurrent
    {
      get
      {
        object o = ViewState["IsCurrent"];
        if (o != null)
          return (Boolean)o;
        else
          return _userIsCurrent;
      }

      set { _userIsCurrent = value; }
    }

    protected override void CreateChildControls()
    {
      Controls.Clear();

      NickNameLabel = new Label();
      NickNameLabel.Text = this.NickName;
      SetControlAttributes(NickNameLabel);

      PetNameLabel = new Label();
      PetNameLabel.Text = this.PetName;
      SetControlAttributes(PetNameLabel);

      SpecialDateLabel = new Label();
      SpecialDateLabel.Text = this.SpecialDay.ToShortDateString();
      SetControlAttributes(SpecialDateLabel);

      IsCurrentCheckBox = new CheckBox();
      IsCurrentCheckBox.Checked = this.IsCurrent;
      SetControlAttributes(IsCurrentCheckBox);

      JobTypeLabel = new Label();
      JobTypeLabel.Text = this.UserJobType.ToString();
      SetControlAttributes(JobTypeLabel);

      ChildControlsCreated = true;
    }

    private void SetControlAttributes(WebControl ctl)
    {
      ctl.BackColor = Color.White;
      ctl.BorderWidth = 1;
      ctl.Width = 200;
      this.Controls.Add(ctl);
    }

    protected override void RenderContents(HtmlTextWriter writer)
    {
      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);
    }
  }

  [AspNetHostingPermission(SecurityAction.Demand,
    Level = AspNetHostingPermissionLevel.Minimal)]
  [AspNetHostingPermission(SecurityAction.InheritanceDemand,
    Level = AspNetHostingPermissionLevel.Minimal)]
  public class TextDisplayWebPart : WebPart
  {
    private String _contentText = null;
    TextBox input;
    Label DisplayContent;
    Literal lineBreak;

    [Personalizable(), WebBrowsable]
    public String ContentText
    {
      get { return _contentText; }
      set { _contentText = value; }
    }

    protected override void CreateChildControls()
    {
      Controls.Clear();
      DisplayContent = new Label();
      DisplayContent.BackColor = Color.LightBlue;
      DisplayContent.Text = this.ContentText;
      this.Controls.Add(DisplayContent);

      lineBreak = new Literal();
      lineBreak.Text = @"<br />";
      Controls.Add(lineBreak);

      input = new TextBox();
      this.Controls.Add(input);
      Button update = new Button();
      update.Text = "Set Label Content";
      update.Click += new EventHandler(this.submit_Click);
      this.Controls.Add(update);
    }

    private void submit_Click(object sender, EventArgs e)
    {
      // Update the label string.
      if (!string.IsNullOrEmpty(input.Text))
      {
        _contentText = input.Text + @"<br />";
        input.Text = String.Empty;
        DisplayContent.Text = this.ContentText;
      }
    }
  }
}

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

La terza parte dell'esempio è la pagina Web che contiene il PageCatalogPart controllo . Si noti che il Button1_Click metodo chiama il GetAvailableWebPartDescriptions metodo , ottiene le descrizioni dei WebPart controlli nel catalogo di pagine e scrive i dettagli in un'etichetta.

<%@ page language="c#" %>
<%@ register TagPrefix="uc1" 
  TagName="DisplayModeMenuCS" 
  Src="DisplayModeMenuCS.ascx" %>
<%@ register tagprefix="aspSample" 
  Namespace="Samples.AspNet.CS.Controls" 
  Assembly="UserInfoWebPartCS" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
  
  protected void Page_Load(object sender, EventArgs e)
  {
    Button1.Visible = false;
    Button2.Visible = false;
    Label1.Visible = false;
  }

  // <snippet3>
  protected void Button1_Click(object sender, EventArgs e)
  {
    WebPartDescriptionCollection descriptions =
      PageCatalogPart1.GetAvailableWebPartDescriptions();
    StringBuilder descriptionContent = new StringBuilder();
    foreach (WebPartDescription description in descriptions)
    {
      descriptionContent.AppendLine("<div><br /><strong>" + description.Title + 
        "</strong><br />");
      descriptionContent.AppendLine(" ID: " + description.ID + "<br />");
      descriptionContent.AppendLine(" Description: " + 
        description.Description + "<br /></div><hr />");
    }

    Label1.Text = "<h3>Catalog Contents</h3>" + descriptionContent.ToString();    
  }
  // </snippet3>

  // <snippet4>
  protected void Button2_Click(object sender, EventArgs e)
  {
    WebPartDescriptionCollection descriptions = 
      PageCatalogPart1.GetAvailableWebPartDescriptions();  
      
    if(descriptions.Count > 0)
    {
      ArrayList partList = new ArrayList();
      
      // Add the WebPart controls to a collection before you call 
      // AddWebPart on the WebPartManager.  If you try to add the 
      // controls directly by using AddWebPart, the WebPartAdded 
      // event fires each time you call AddWebPart, and it destroys  
      // the collection of descriptions before you finish adding 
      // all the WebPart controls.
      foreach(WebPartDescription description in descriptions)
      {
        WebPart partToAdd = 
          PageCatalogPart1.GetWebPart(description);
        partList.Add(partToAdd);
      }
      
      foreach(WebPart part in partList)
      {
        WebPartManager1.AddWebPart(part, zone1, 0);
      }
    }  
  }
  // </snippet4>

  protected void PageCatalogPart1_PreRender(object sender,
    EventArgs e)
  {
    Button1.Visible = true;
    Button2.Visible = true;
    Label1.Visible = true;
  }

</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>
      DeclarativeCatalogPart Control
    </title>
  </head>
  <body>
    <form id="form1" runat="server">
      <asp:webpartmanager id="WebPartManager1" runat="server"  />
      <uc1:DisplayModeMenuCS 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> 
      <div>
      <hr />
      <asp:Button ID="Button1" runat="server" 
        Text="Display WebPart descriptions" 
        OnClick="Button1_Click" />
      <br />
      <asp:Button ID="Button2" runat="server" 
        Text="Add WebPart Controls" OnClick="Button2_Click" />
      <asp:Label ID="Label1" runat="server" Text="" />
      </div>
      <asp:CatalogZone ID="CatalogZone1" runat="server">
        <ZoneTemplate>
          <asp:PageCatalogPart ID="PageCatalogPart1" runat="server" 
            OnPreRender="PageCatalogPart1_PreRender" />
          <asp:DeclarativeCatalogPart ID="DeclarativeCatalogPart1"  
            runat="server" 
            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 where users can dynamically 
                  update the text." />
            </WebPartsTemplate>              
          </asp:DeclarativeCatalogPart>
        </ZoneTemplate>
      </asp:CatalogZone>
    </form>
  </body>
</html>

<%@ page language="VB" Debug="true" %>
<%@ register TagPrefix="uc1" 
  TagName="DisplayModeMenuVB" 
  Src="DisplayModeMenuVB.ascx" %>
<%@ register tagprefix="aspSample" 
  Namespace="Samples.AspNet.VB.Controls" 
  Assembly="UserInfoWebPartVB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  Protected Sub Page_Load(ByVal sender As Object, _
    ByVal e As System.EventArgs)
    Button1.Visible = False
    Button2.Visible = False
    Label1.Visible = False
  End Sub

  ' <snippet3>
  Shared editControlTitle As String
  
  Protected Sub Button1_Click(ByVal sender As Object, _
    ByVal e As System.EventArgs)

    Dim descriptions As WebPartDescriptionCollection = _
      PageCatalogPart1.GetAvailableWebPartDescriptions()
    Dim descriptionContent As StringBuilder = New StringBuilder()
    Dim description As WebPartDescription
    For Each description In descriptions
      descriptionContent.AppendLine("<div><br /><strong>" + _
        description.Title + "</strong><br />")
      descriptionContent.AppendLine(" ID: " + _
        description.ID + "<br />")
      descriptionContent.AppendLine(" Description: " + _
        description.Description + "<br /></div><hr />")
    Next description

    Label1.Text = "<h3>Catalog Contents</h3>" + descriptionContent.ToString()
    
  End Sub
  ' </snippet3>
  
  ' <snippet4>
  Protected Sub Button2_Click(ByVal sender As Object, _
    ByVal e As System.EventArgs)
    
    Dim descriptions As WebPartDescriptionCollection = _
      PageCatalogPart1.GetAvailableWebPartDescriptions()
    
    If descriptions.Count > 0 Then
      Dim partList As ArrayList = New ArrayList()
      Dim description As WebPartDescription
      Dim part As WebPart

      ' Add the WebPart controls to a collection before you call 
      ' AddWebPart on the WebPartManager.  If you try to add the 
      ' controls directly by using AddWebPart, the WebPartAdded 
      ' event fires each time you call AddWebPart, and it destroys  
      ' the collection of descriptions before you finish adding 
      ' all the WebPart controls.
      For Each description In descriptions
        Dim partToAdd As WebPart = _
          PageCatalogPart1.GetWebPart(description)
        partList.Add(partToAdd)
      Next
      
      For Each part In partList
        WebPartManager1.AddWebPart(part, zone1, 0)
      Next
      
    End If
    
  End Sub
  ' </snippet4>

  Protected Sub PageCatalogPart1_PreRender(ByVal _
    sender As Object, ByVal e As System.EventArgs)
    Button1.Visible = True
    Button2.Visible = True
    Label1.Visible = True
  End Sub

</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
  <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> 
      <div>
      <hr />
      <asp:Button ID="Button1" runat="server" 
        Text="Display WebPart descriptions" 
        OnClick="Button1_Click" />
      <br />
      <asp:Button ID="Button2" runat="server" 
        Text="Add WebPart Controls" OnClick="Button2_Click" />
      <asp:Label ID="Label1" runat="server" Text="" />
      </div>
      <asp:CatalogZone ID="CatalogZone1" runat="server">
        <ZoneTemplate>
          <asp:PageCatalogPart ID="PageCatalogPart1" runat="server" 
            OnPreRender="PageCatalogPart1_PreRender" />
          <asp:DeclarativeCatalogPart ID="DeclarativeCatalogPart1"  
            runat="server" 
            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 where users can dynamically 
                  update the text." />
            </WebPartsTemplate>              
          </asp:DeclarativeCatalogPart>
        </ZoneTemplate>
      </asp:CatalogZone>
    </form>
  </body>
</html>

Quando si carica la pagina in un browser, selezionare Modalità catalogo nel controllo elenco a discesa Modalità di visualizzazione per passare alla modalità catalogo. In modalità catalogo è possibile visualizzare i controlli disponibili per l'aggiunta alla pagina. Aggiungere uno o più controlli alla pagina e quindi usare il controllo elenco a discesa Modalità di visualizzazione per restituire la pagina in modalità di esplorazione. Fare clic sul menu dei verbi (freccia verso il basso) nella barra del titolo di uno o più controlli e fare clic su Chiudi. Restituisce la pagina in modalità catalogo e si noti che il controllo o i controlli chiusi ora vengono visualizzati nel catalogo di pagine e sono disponibili per essere aggiunti di nuovo alla pagina. Fare clic sul pulsante Visualizza descrizioni webpart per scrivere i dettagli sui controlli nel catalogo di pagine nell'etichetta.

Commenti

Il GetAvailableWebPartDescriptions metodo fornisce un'implementazione per il metodo di base astratto dichiarato nella CatalogPart classe . Il GetAvailableWebPartDescriptions metodo restituisce informazioni di descrizione per ogni controllo in un catalogo. Un WebPartDescription oggetto contiene informazioni essenziali su un WebPart controllo, incluso il relativo ID, un riferimento all'oggetto al controllo e i valori di diverse proprietà importanti ereditate dalla Part classe , ad esempio Title e Description.

Il GetAvailableWebPartDescriptions metodo migliora le prestazioni. Quando viene creato un catalogo, sono necessarie alcune informazioni su ogni controllo che contiene, tra cui un titolo, una descrizione, un'icona (se presente) e un ID. Invece di creare un'istanza di ogni controllo per ottenere queste informazioni, una CatalogZoneBase zona che crea un catalogo chiama il GetAvailableWebPartDescriptions metodo per ogni controllo che si troverà nel catalogo e la chiamata restituisce solo le informazioni di descrizione per il controllo.

Vedi anche

• GetAvailableWebPartDescriptions()
• controlli web part ASP.NET