ListView.SelectedIndexChanged Evento

Referencia

Definición

Espacio de nombres:: System.Web.UI.WebControls

Ensamblado:: System.Web.Extensions.dll

Importante

Parte de la información hace referencia a la versión preliminar del producto, que puede haberse modificado sustancialmente antes de lanzar la versión definitiva. Microsoft no otorga ninguna garantía, explícita o implícita, con respecto a la información proporcionada aquí.

Se produce cuando se hace clic en el botón Seleccionar de un elemento, después de que el control ListView administre la operación de selección.

public:
 event EventHandler ^ SelectedIndexChanged;

public event EventHandler SelectedIndexChanged;

member this.SelectedIndexChanged : EventHandler

Public Custom Event SelectedIndexChanged As EventHandler

Tipo de evento

EventHandler

Ejemplos

En el ejemplo siguiente se muestra cómo crear un controlador de eventos para el SelectedIndexChanged evento.

<%@ 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">
    
  //<Snippet3>
  void ContactsListView_SelectedIndexChanged(Object sender, EventArgs e)
  {
    if (ContactsListView.SelectedIndex >= 0)
      ViewState["SelectedKey"] = ContactsListView.SelectedValue;
    else
      ViewState["SelectedKey"] = null;
  }
  
  void ContactsListView_DataBound(Object sender, EventArgs e)
  {
    for (int i = 0; i < ContactsListView.Items.Count; i++)
    {
      // Ignore values that cannot be cast as integer.
      try
      {
          if ((int)ContactsListView.DataKeys[i].Value == (int)ViewState["SelectedKey"])
              ContactsListView.SelectedIndex = i;
      }
      catch { }
    }
  }
  //</Snippet3>

  void ContactsListView_PagePropertiesChanged(Object sender, EventArgs e)
  {
    ContactsListView.SelectedIndex = -1;
  }

  void ContactsListView_Sorting(Object sender, ListViewSortEventArgs e)
  {
    ContactsListView.SelectedIndex = -1;
  }

  void ClearButton_Click(Object sender, EventArgs e)
  {
    ViewState["SelectedKey"] = null;
    ContactsListView.SelectedIndex = -1;
  }
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head id="Head1" runat="server">
    <title>ListView SelectedIndex Example</title>
  </head>
  <body>
    <form id="form1" runat="server">
        
      <h3>ListView SelectedIndex Example</h3>

      <asp:ListView ID="ContactsListView" 
        DataSourceID="ContactsDataSource" 
        DataKeyNames="ContactID"
        OnDataBound="ContactsListView_DataBound"
        OnSelectedIndexChanged="ContactsListView_SelectedIndexChanged"  
        OnPagePropertiesChanged="ContactsListView_PagePropertiesChanged"
        OnSorting="ContactsListView_Sorting"
        runat="server">
        <LayoutTemplate>
          <asp:Button runat="server" ID="SortButton" 
            CommandArgument="LastName" CommandName="Sort" Text="Sort" />
          <asp:Button runat="server" ID="ClearButton" 
            OnClick="ClearButton_Click" Text="Clear Selection" /><br />
          <table cellpadding="2" border="1" runat="server" id="tblContacts" width="640px">
            <tr runat="server" id="itemPlaceholder" />
          </table>
          <asp:DataPager runat="server" ID="PeopleDataPager" PageSize="20">
            <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 valign="top">
              <asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
              <asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
            </td>
            <td>
              <asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
            </td>
            <td>
              <asp:LinkButton ID="SelectButton" runat="server" CommandName="Select" Text="Select" />
            </td>
          </tr>
        </ItemTemplate>
        <SelectedItemTemplate>
          <tr runat="server" style="background-color:#B0C4DE">
            <td valign="top">
              <asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
              <asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
            </td>
            <td>
              <asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
            </td>
            <td>&nbsp;</td>
          </tr>
        </SelectedItemTemplate>
      </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">
    
  '<Snippet3>
  Sub ContactsListView_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
    If ContactsListView.SelectedIndex >= 0 Then
      ViewState("SelectedKey") = ContactsListView.SelectedValue
    Else
      ViewState("SelectedKey") = Nothing
    End If
  End Sub

  Sub ContactsListView_DataBound(ByVal sender As Object, ByVal e As EventArgs)
    For i As Integer = 0 To ContactsListView.Items.Count - 1
      ' Ignore values that cannot be cast as integer.
      Try
        If Convert.ToInt32(ContactsListView.DataKeys(i).Value) = Convert.ToInt32(ViewState("SelectedKey")) Then _
          ContactsListView.SelectedIndex = i
      Catch
      End Try
    Next
  End Sub
  '</Snippet3>

  Sub ContactsListView_PagePropertiesChanged(ByVal sender As Object, ByVal e As EventArgs)
    ContactsListView.SelectedIndex = -1
  End Sub

  Sub ContactsListView_Sorting(ByVal sender As Object, ByVal e As ListViewSortEventArgs)
    ContactsListView.SelectedIndex = -1
  End Sub

  Sub ClearButton_Click(ByVal sender As Object, ByVal e As EventArgs)
    ViewState("SelectedKey") = Nothing
    ContactsListView.SelectedIndex = -1
  End Sub
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head id="Head1" runat="server">
    <title>ListView SelectedIndex Example</title>
  </head>
  <body>
    <form id="form1" runat="server">
        
      <h3>ListView SelectedIndex Example</h3>

      <asp:ListView ID="ContactsListView" 
        DataSourceID="ContactsDataSource" 
        DataKeyNames="ContactID"
        OnDataBound="ContactsListView_DataBound"
        OnSelectedIndexChanged="ContactsListView_SelectedIndexChanged"  
        OnPagePropertiesChanged="ContactsListView_PagePropertiesChanged"
        OnSorting="ContactsListView_Sorting"
        runat="server">
        <LayoutTemplate>
          <asp:Button runat="server" ID="SortButton" 
            CommandArgument="LastName" CommandName="Sort" Text="Sort" />
          <asp:Button runat="server" ID="ClearButton" 
            OnClick="ClearButton_Click" Text="Clear Selection" /><br />
          <table cellpadding="2" border="1" runat="server" id="tblContacts" width="640px">
            <tr runat="server" id="itemPlaceholder" />
          </table>
          <asp:DataPager runat="server" ID="PeopleDataPager" PageSize="20">
            <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 valign="top">
              <asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
              <asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
            </td>
            <td>
              <asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
            </td>
            <td>
              <asp:LinkButton ID="SelectButton" runat="server" CommandName="Select" Text="Select" />
            </td>
          </tr>
        </ItemTemplate>
        <SelectedItemTemplate>
          <tr runat="server" style="background-color:#B0C4DE">
            <td valign="top">
              <asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
              <asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
            </td>
            <td>
              <asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
            </td>
            <td>&nbsp;</td>
          </tr>
        </SelectedItemTemplate>
      </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>

Comentarios

El SelectedIndexChanged evento se genera cuando se hace clic en el botón Seleccionar de un elemento, después de que el ListView control control controle la operación de selección. (Un botón Seleccionar es un control de botón cuya CommandName propiedad está establecida en "Seleccionar"). Esto le permite realizar una rutina personalizada cada vez que se produzca este evento, como actualizar una etiqueta de estado con información sobre el elemento seleccionado actualmente.

Para obtener más información acerca de cómo controlar eventos, vea controlar y provocar eventos.

Se aplica a

ListView.SelectedIndexChanged Evento

Definición

Tipo de evento

Ejemplos

Comentarios

Se aplica a

Consulte también

Comentarios

Recursos adicionales