ListViewSortEventArgs Classe

  • Riferimento

Definizione

Spazio dei nomi:
System.Web.UI.WebControls
Assembly:
System.Web.Extensions.dll

Fornisce i dati per l'evento Sorting.

public ref class ListViewSortEventArgs : System::ComponentModel::CancelEventArgs
public class ListViewSortEventArgs : System.ComponentModel.CancelEventArgs
type ListViewSortEventArgs = class
    inherit CancelEventArgs
Public Class ListViewSortEventArgs
Inherits CancelEventArgs
Ereditarietà
Object
EventArgs
CancelEventArgs
ListViewSortEventArgs

Esempio

Nell'esempio seguente viene illustrato come usare l'oggetto ListViewSortEventArgs per visualizzare la direzione di ordinamento e la colonna che viene ordinata.

<%@ Page language="C#" %>
    
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    
<script runat="server">
  //<Snippet2>
  void ContactsListView_Sorting(Object sender, ListViewSortEventArgs e)
  {
    // Check the sort direction to set the image URL accordingly.
    string imgUrl;
    if (e.SortDirection == SortDirection.Ascending)
      imgUrl = "~/images/ascending.gif";
    else
      imgUrl = "~/images/descending.gif";
      
    // Check which field is being sorted
    // to set the visibility of the image controls.
    Image sortImage1 = (Image) ContactsListView.FindControl("SortImage1");
    Image sortImage2 = (Image)ContactsListView.FindControl("SortImage2");
    Image sortImage3 = (Image)ContactsListView.FindControl("SortImage3");
    switch (e.SortExpression)
    {
      case "FirstName":
        sortImage1.Visible = true;
        sortImage1.ImageUrl = imgUrl;
        sortImage2.Visible = false;
        sortImage3.Visible = false;
        break;
      case "LastName":
        sortImage1.Visible = false;
        sortImage2.Visible = true;
        sortImage2.ImageUrl = imgUrl;
        sortImage3.Visible = false;
        break;
      case "EmailAddress":
        sortImage1.Visible = false;
        sortImage2.Visible = false;
        sortImage3.Visible = true;
        sortImage3.ImageUrl = imgUrl;
        break;
    }
  }
  //</Snippet2>
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head id="Head1" runat="server">
    <title>ListView Sorting Example</title>
    <style type="text/css">
      body  { font: 10pt Trebuchet MS, Arial, Tahoma; }
      td { border: 1px solid #E6E6FA; }
      .header {	background: #B0C4DE; }
      .alternatingItem { background: #edf5fd; }
    </style>
  </head>
  <body>
    <form id="form1" runat="server">
        
      <h3>ListView Sorting Example</h3>
      
      <asp:ListView ID="ContactsListView" 
        DataSourceID="ContactsDataSource" 
        OnSorting="ContactsListView_Sorting"
        runat="server">
        <LayoutTemplate>
          <table width="640px" runat="server" id="tblContacts">
            <tr class="header" align="center" runat="server">
              <td>
                <asp:LinkButton runat="server" ID="SortByFirstNameButton"
                  CommandName="Sort" Text="First Name" 
                  CommandArgument="FirstName"/>
                <asp:Image runat="server" ID="SortImage1" 
                  ImageUrl="~/images/ascending.gif" Visible="false" />
              </td>
              <td>
                <asp:LinkButton runat="server" ID="SortByLastNameButton"
                  CommandName="Sort" Text="Last Name"
                  CommandArgument="LastName" />
                <asp:Image runat="server" ID="SortImage2" 
                  ImageUrl="~/images/ascending.gif" Visible="false" />
              </td>
              <td>
                <asp:LinkButton runat="server" ID="SortByEmailButton"
                  CommandName="Sort" Text="Email Address" 
                  CommandArgument="EmailAddress" />
                <asp:Image runat="server" ID="SortImage3" 
                  ImageUrl="~/images/ascending.gif" Visible="false" />
              </td>
            </tr>
            <tr runat="server" id="itemPlaceholder" />
          </table>
          <asp:DataPager runat="server" ID="PeopleDataPager" PageSize="12">
            <Fields>
              <asp:NextPreviousPagerField 
                ShowFirstPageButton="true" ShowLastPageButton="true"
                FirstPageText="|&lt;&lt; " LastPageText=" &gt;&gt;|"
                NextPageText=" &gt; " PreviousPageText=" &lt; " />
            </Fields>
          </asp:DataPager>
        </LayoutTemplate>
        <ItemTemplate>
          <tr runat="server">
            <td>
              <asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
            </td>
            <td>
              <asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
            </td>
            <td>
              <asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
            </td>
          </tr>
        </ItemTemplate>
        <AlternatingItemTemplate>
          <tr class="alternatingItem" runat="server">
            <td>
              <asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
            </td>
            <td>
              <asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
            </td>
            <td>
              <asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
            </td>
          </tr>
        </AlternatingItemTemplate>
      </asp:ListView>
      
      <!-- This example uses Microsoft SQL Server and connects    -->
      <!-- to the AdventureWorks sample database. Use an ASP.NET  -->
      <!-- expression to retrieve the connection string value     -->
      <!-- from the Web.config file.                              -->
      <asp:SqlDataSource ID="ContactsDataSource" runat="server" 
        ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>"
        SelectCommand="SELECT [ContactID], [FirstName], [LastName], [EmailAddress] 
          FROM Person.Contact" >
      </asp:SqlDataSource>
      
    </form>
  </body>
</html>

<%@ Page language="VB" %>
    
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    
<script runat="server">
 '<Snippet2>
  Sub ContactsListView_Sorting(ByVal sender As Object, ByVal e As ListViewSortEventArgs) 
  
    ' Check the sort direction to set the image URL accordingly.
    Dim imgUrl As String
    If e.SortDirection = SortDirection.Ascending Then
      imgUrl = "~/images/ascending.gif"
    Else
      imgUrl = "~/images/descending.gif"
    End If
    
    ' Check which field is being sorted
    ' to set the visibility of the image controls.
    Dim sortImage1 As Image = CType(ContactsListView.FindControl("SortImage1"), Image)
    Dim sortImage2 As Image = CType(ContactsListView.FindControl("SortImage2"), Image)
    Dim sortImage3 As Image = CType(ContactsListView.FindControl("SortImage3"), Image)
    
    Select Case e.SortExpression
      Case "FirstName"
        sortImage1.Visible = True
        sortImage1.ImageUrl = imgUrl
        sortImage2.Visible = False
        sortImage3.Visible = False
      Case "LastName"
        sortImage1.Visible = False
        sortImage2.Visible = True
        sortImage2.ImageUrl = imgUrl
        sortImage3.Visible = False
      Case "EmailAddress"
        sortImage1.Visible = False
        sortImage2.Visible = False
        sortImage3.Visible = True
        sortImage3.ImageUrl = imgUrl
    End Select
    
  End Sub
  '</Snippet2>
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head id="Head1" runat="server">
    <title>ListView Sorting Example</title>
    <style type="text/css">
      body  { font: 10pt Trebuchet MS, Arial, Tahoma; }
      td { border: 1px solid #E6E6FA; }
      .header {	background: #B0C4DE; }
      .alternatingItem { background: #edf5fd; }
    </style>
  </head>
  <body>
    <form id="form1" runat="server">
        
      <h3>ListView Sorting Example</h3>
      
      <asp:ListView ID="ContactsListView" 
        DataSourceID="ContactsDataSource" 
        OnSorting="ContactsListView_Sorting"
        runat="server">
        <LayoutTemplate>
          <table width="640px" runat="server" id="tblContacts">
            <tr class="header" align="center" runat="server">
              <td>
                <asp:LinkButton runat="server" ID="SortByFirstNameButton"
                  CommandName="Sort" Text="First Name" 
                  CommandArgument="FirstName"/>
                <asp:Image runat="server" ID="SortImage1" 
                  ImageUrl="~/images/ascending.gif" Visible="false" />
              </td>
              <td>
                <asp:LinkButton runat="server" ID="SortByLastNameButton"
                  CommandName="Sort" Text="Last Name"
                  CommandArgument="LastName" />
                <asp:Image runat="server" ID="SortImage2" 
                  ImageUrl="~/images/ascending.gif" Visible="false" />
              </td>
              <td>
                <asp:LinkButton runat="server" ID="SortByEmailButton"
                  CommandName="Sort" Text="Email Address" 
                  CommandArgument="EmailAddress" />
                <asp:Image runat="server" ID="SortImage3" 
                  ImageUrl="~/images/ascending.gif" Visible="false" />
              </td>
            </tr>
            <tr runat="server" id="itemPlaceholder" />
          </table>
          <asp:DataPager runat="server" ID="PeopleDataPager" PageSize="12">
            <Fields>
              <asp:NextPreviousPagerField 
                ShowFirstPageButton="true" ShowLastPageButton="true"
                FirstPageText="|&lt;&lt; " LastPageText=" &gt;&gt;|"
                NextPageText=" &gt; " PreviousPageText=" &lt; " />
            </Fields>
          </asp:DataPager>
        </LayoutTemplate>
        <ItemTemplate>
          <tr runat="server">
            <td>
              <asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
            </td>
            <td>
              <asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
            </td>
            <td>
              <asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
            </td>
          </tr>
        </ItemTemplate>
        <AlternatingItemTemplate>
          <tr class="alternatingItem" runat="server">
            <td>
              <asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
            </td>
            <td>
              <asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
            </td>
            <td>
              <asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
            </td>
          </tr>
        </AlternatingItemTemplate>
      </asp:ListView>
      
      <!-- This example uses Microsoft SQL Server and connects    -->
      <!-- to the AdventureWorks sample database. Use an ASP.NET  -->
      <!-- expression to retrieve the connection string value     -->
      <!-- from the Web.config file.                              -->
      <asp:SqlDataSource ID="ContactsDataSource" runat="server" 
        ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>"
        SelectCommand="SELECT [ContactID], [FirstName], [LastName], [EmailAddress] 
          FROM Person.Contact" >
      </asp:SqlDataSource>
      
    </form>
  </body>
</html>

Commenti

Il ListView controllo genera l'evento Sorting quando viene fatto clic su un pulsante Ordina, ma prima del ListView controllo gestisce l'operazione di ordinamento. Un pulsante Sort è un pulsante la cui CommandName proprietà è impostata su "Sort". Ciò consente di fornire un metodo di gestione eventi che esegue una routine personalizzata ogni volta che si verifica questo evento, ad esempio personalizzando l'espressione di ordinamento.

Un ListViewSortEventArgs oggetto viene passato al metodo di gestione degli eventi. Questo oggetto consente di specificare o determinare l'espressione di ordinamento e la direzione di ordinamento per il ListView controllo. Per determinare l'espressione di ordinamento, usare la SortExpression proprietà . Per determinare la direzione di ordinamento, usare la SortDirection proprietà . È anche possibile annullare un'operazione di ordinamento impostando la Cancel proprietà su true.

Per un elenco dei valori iniziali delle proprietà di un'istanza della classe ListViewSortEventArgs, vedere il costruttore ListViewSelectEventArgs.

Costruttori

ListViewSortEventArgs(String, SortDirection)

Inizializza una nuova istanza della classe ListViewSortEventArgs.

Proprietà

Cancel

Ottiene o imposta un valore che indica se l'evento debba essere annullato.

(Ereditato da CancelEventArgs)
SortDirection

Ottiene o imposta la direzione in cui ordinare il controllo ListView.
SortExpression

Ottiene o imposta l'espressione utilizzata per ordinare gli elementi nel controllo ListView.

Metodi

Equals(Object)

Determina se l'oggetto specificato è uguale all'oggetto corrente.

(Ereditato da Object)
GetHashCode()

Funge da funzione hash predefinita.

(Ereditato da Object)
GetType()

Ottiene l'oggetto Type dell'istanza corrente.

(Ereditato da Object)
MemberwiseClone()

Crea una copia superficiale dell'oggetto Object corrente.

(Ereditato da Object)
ToString()

Restituisce una stringa che rappresenta l'oggetto corrente.

(Ereditato da Object)

Si applica a

Vedi anche