WebPartDescription 类

  • 参考

定义

命名空间:
System.Web.UI.WebControls.WebParts
程序集:
System.Web.dll

提供 WebPart 控件的有关信息，该控件无需创建实例即可显示在 Web 部件控件目录中。

public ref class WebPartDescription
public class WebPartDescription
type WebPartDescription = class
Public Class WebPartDescription
继承
Object
WebPartDescription

示例

下面的代码示例演示如何以编程方式使用 WebPartDescription 类。 通常，此类型主要由 Web 部件控件集使用，但此代码示例只是显示主要说明属性的基本编程用法。

该代码示例包含四个部分：

  • 一个用户控件，使用户能够更改网页上的显示模式。

  • 自定义 WebPart 控件。

  • 用于托管其他控件的网页。

  • 代码示例工作原理的说明。

代码示例的第一部分是用户控件。 用户控件的源代码来自另一个主题。 有关用户控件的更多详细信息，请参阅主题 演练：更改 Web 部件页上的显示模式。

<%@ 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="&nbsp;Display Mode" 
      Font-Bold="true"
      Font-Size="8"
      Width="120" 
      AssociatedControlID="DisplayModeDropdown"/>
    <div>
    <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" />
    </div>
    <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="&nbsp;Display Mode" 
      Font-Bold="true"
      Font-Size="8"
      Width="120" 
      AssociatedControlID="DisplayModeDropdown"/>
    <div>
    <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" />
    </div>
    <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>

代码示例的第二部分是自定义 WebPart 控件。 若要运行代码示例，必须编译此源代码。 可以显式编译它，并将生成的程序集放入网站的 Bin 文件夹或全局程序集缓存中。 或者，可以将源代码放入站点的App_Code文件夹中，在运行时将动态编译源代码。 此代码示例使用动态编译的方法。 有关演示如何编译的演练，请参阅 演练：开发和使用自定义 Web 服务器控件。

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 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 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

代码示例的第三部分是网页。 顶部附近是两 Register 个指令：一个用于注册用户控件，另一个用于注册其源文件位于站点App_Code文件夹中的自定义 WebPart 控件。 该页包含一个<asp:catalogzone>元素，该元素又包含对两个控件的声明性引用：名为 的TextDisplayWebPart自定义WebPart控件，以及一个 BulletedList Web 服务器控件，该控件将在运行时被视为控件WebPart，因为该WebPartManager控件会用 GenericWebPart 对象包装它。 请注意，在 方法的代码Button1_Click中，使用 GetAvailableWebPartDescriptions 方法检索目录中控件的可用WebPartDescription对象WebPart，然后将说明详细信息全部写出到页面。

<%@ Page Language="C#" %>
<%@ Register TagPrefix="uc1"
    TagName="DisplayModeMenuCS"
    Src="~/DisplayModeMenuCS.ascx" %>
<%@ Register TagPrefix="aspSample" 
    Namespace="Samples.AspNet.CS.Controls"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

  // <snippet2>
  protected void Button1_Click(object sender, EventArgs e)
  {
    Label1.Text = String.Empty;
    
    WebPartDescriptionCollection descriptions = 
      DeclarativeCatalogPart1.GetAvailableWebPartDescriptions();

    foreach (WebPartDescription desc in descriptions)
    {
      Label1.Text += "ID: " + desc.ID + "<br />" +
        "Title: " + desc.Title + "<br />" +
        "Description: " + desc.Description + "<br />" +
        "ImageUrl: " + desc.CatalogIconImageUrl + "<br />" +
        "<hr />";
    }
  }
  // </snippet2>

  protected void Page_PreRender(object sender, EventArgs e)
  {
    if (mgr1.DisplayMode == WebPartManager.CatalogDisplayMode)
    {
      Button1.Visible = true;
      Label1.Visible = true;
    }
    else
    {
      Button1.Visible = false;
      Label1.Visible = false;
    }
  }
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
  <title>Untitled Page</title>
</head>
<body>
  <form id="form1" runat="server">
    <asp:WebPartManager ID="mgr1" runat="server">
    </asp:WebPartManager>
    <uc1:DisplayModeMenuCS ID="menu1" runat="server" />
    <asp:WebPartZone ID="WebPartZone1" runat="server">
      <ZoneTemplate>
        <asp:Calendar ID="Calendar1" runat="server"></asp:Calendar>
      </ZoneTemplate>
    </asp:WebPartZone>
    <asp:CatalogZone ID="CatalogZone1" runat="server">
      <ZoneTemplate>
        <asp:DeclarativeCatalogPart ID="DeclarativeCatalogPart1" runat="server">
          <WebPartsTemplate>
            <aspSample:TextDisplayWebPart ID="txtDisplayWebPart1" runat="server"
              Title="Text Display"
              Description="Displays entered text in a label control."
              CatalogIconImageUrl="MyWebPartIcon.gif" 
              />
            <asp:BulletedList 
              ID="BulletedList1"
              Runat="server"
              DisplayMode="HyperLink" 
              Title="Favorite Links"
              CatalogIconImageUrl="MyLinksIcon.gif"
              Description="My Favorite Links">
              <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>
          </WebPartsTemplate>
        </asp:DeclarativeCatalogPart>
      </ZoneTemplate>
    </asp:CatalogZone> 
    <hr />
    <asp:Button ID="Button1" runat="server" 
      Text="List WebPartDescription Info" OnClick="Button1_Click" /> 
    <br />
    <asp:Label ID="Label1" runat="server" Text="" />
    <div>
    </div>
  </form>
</body>
</html>

<%@ Page Language="vb" %>
<%@ Register TagPrefix="uc1"
    TagName="DisplayModeMenuVB"
    Src="~/DisplayModeMenuVB.ascx" %>
<%@ Register TagPrefix="aspSample" 
    Namespace="Samples.AspNet.VB.Controls"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

  ' <snippet2>
  Protected Sub Button1_Click(ByVal sender As Object, _
    ByVal e As System.EventArgs)
    
    Label1.Text = String.Empty
        
    Dim descriptions As WebPartDescriptionCollection = _
     DeclarativeCatalogPart1.GetAvailableWebPartDescriptions()
            
    Dim desc As WebPartDescription
        
    For Each desc In descriptions
      Label1.Text += "ID: " & desc.ID & "<br />" & _
        "Title: " & desc.Title & "<br />" & _
        "Description: " & desc.Description & "<br />" & _
        "ImageUrl: " & desc.CatalogIconImageUrl & "<br />" & _
        "<hr />"
    Next
    
  End Sub
  ' </snippet2>

  Protected Sub Page_PreRender(ByVal sender As Object, _
    ByVal e As System.EventArgs)
        
    If mgr1.DisplayMode Is WebPartManager.CatalogDisplayMode Then
      Button1.Visible = True
      Label1.Visible = True
    Else
      Button1.Visible = False
      Label1.Visible = False
    End If
        
  End Sub


</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
  <title>Untitled Page</title>
</head>
<body>
  <form id="form1" runat="server">
    <asp:WebPartManager ID="mgr1" runat="server">
    </asp:WebPartManager>
    <uc1:DisplayModeMenuVB ID="menu1" runat="server" />
    <asp:WebPartZone ID="WebPartZone1" runat="server">
      <ZoneTemplate>
        <asp:Calendar ID="Calendar1" runat="server"></asp:Calendar>
      </ZoneTemplate>
    </asp:WebPartZone>
    <asp:CatalogZone ID="CatalogZone1" runat="server">
      <ZoneTemplate>
        <asp:DeclarativeCatalogPart ID="DeclarativeCatalogPart1" runat="server">
          <WebPartsTemplate>
            <aspSample:TextDisplayWebPart ID="txtDisplayWebPart1" runat="server"
              Title="Text Display"
              Description="Displays entered text in a label control."
              CatalogIconImageUrl="MyWebPartIcon.gif" 
              />
            <asp:BulletedList 
              ID="BulletedList1"
              Runat="server"
              DisplayMode="HyperLink" 
              Title="Favorite Links"
              CatalogIconImageUrl="MyLinksIcon.gif"
              Description="My Favorite Links">
              <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>
          </WebPartsTemplate>
        </asp:DeclarativeCatalogPart>
      </ZoneTemplate>
    </asp:CatalogZone> 
    <hr />
    <asp:Button ID="Button1" runat="server" 
      Text="List WebPartDescription Info" OnClick="Button1_Click" /> 
    <br />
    <asp:Label ID="Label1" runat="server" Text="" />
    <div>
    </div>
  </form>
</body>
</html>

在浏览器中加载页面后，使用 “显示模式 ”下拉列表控件并选择“ 目录 ”，将页面更改为目录显示模式。 在目录中，应会看到两个可用于添加到页面的控件。 单击“ 列出 Web 部件说明信息 ”按钮，代码会将所有可用 WebPartDescription 对象的值写入页面。 这演示了可以检索目录中控件的说明详细信息 WebPart ，而无需创建控件本身的实例。

注解

当控件显示在用户可以添加到页面的控件目录中时 WebPart ，需要有关每个控件的一些基本信息。 例如，具有控件的标题和说明很有用，这样当用户查看目录时，他们有足够的信息来决定是否将控件添加到页面。 但是，控件目录 WebPart 可能包含许多控件，如果必须创建每个 WebPart 控件的实例才能提取要在目录中显示的信息，则可能会影响应用程序的性能。

类 WebPartDescription 存在，因此无需创建控件的 WebPart 实例来检索控件目录中显示的控件的相关信息。 在 Web 部件控件集中，当页面处于目录显示模式时， WebPartDescription 对象也与各种 CatalogPart 控件结合使用。

类 WebPartDescription 具有两个 WebPart 其构造函数的重载，一个重载在实例可用时 WebPartDescription 将控件作为参数 (构造函数) ，一个重载将包含控件相关信息的多个字符串作为参数 (WebPartDescription 构造函数) 。

类 WebPartDescription 还具有多个属性，旨在包含控件的说明信息 WebPart 。 下表汇总了 WebPartDescription 属性，以及每个属性在控件中 WebPart 对应的属性。

Description 属性 相关部件控件属性
ID ID
Title Title
Description Description
CatalogIconImageUrl CatalogIconImageUrl

构造函数

WebPartDescription(String, String, String, String)

使用几个包含 WebPart 控件说明信息的字符串初始化类的新实例。
WebPartDescription(WebPart)

如果 WebPart 控件实例可用，则初始化类的新实例。

属性

CatalogIconImageUrl

获取一个 URL，该 URL 包含用作 WebPart 控件图标的图像的路径。
Description

获取 WebPart 控件的说明文本。
ID

获取相应 WebPart 控件的 ID。
Title

获取相应 WebPart 控件的标题文本。

方法

Equals(Object)

确定指定对象是否等于当前对象。

(继承自 Object)
GetHashCode()

作为默认哈希函数。

(继承自 Object)
GetType()

获取当前实例的 Type。

(继承自 Object)
MemberwiseClone()

创建当前 Object 的浅表副本。

(继承自 Object)
ToString()

返回表示当前对象的字符串。

(继承自 Object)

适用于

另请参阅