GridViewCommandEventHandler (Delegado) (System.Web.UI.WebControls)

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Microsoft Visual Studio 2005/.NET Framework 2.0

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GridViewCommandEventHandler (Delegado)

Representa el método que controla el evento RowCommand de un control GridView.

Espacio de nombres: System.Web.UI.WebControls
Ensamblado: System.Web (en system.web.dll)

Sintaxis

Visual Basic (Declaración)

Public Delegate Sub GridViewCommandEventHandler ( _
    sender As Object, _
    e As GridViewCommandEventArgs _
)

Visual Basic (Uso)

Dim instance As New GridViewCommandEventHandler(AddressOf HandlerMethod)

public delegate void GridViewCommandEventHandler (
    Object sender,
    GridViewCommandEventArgs e
)

C++

public delegate void GridViewCommandEventHandler (
    Object^ sender, 
    GridViewCommandEventArgs^ e
)

/** @delegate */
public delegate void GridViewCommandEventHandler (
    Object sender, 
    GridViewCommandEventArgs e
)

JScript

XAML

No aplicable.

Parámetros

sender: Origen del evento.

e: Objeto GridViewCommandEventArgs que contiene los datos del evento.

Comentarios

Se produce el evento RowCommand cuando se hace clic en un botón dentro del control GridView. Esto le permite proporcionar un método de control del evento que realiza una rutina personalizada siempre que este evento se produzca.

Nota:
El control GridView también provoca otros eventos especializados al hacer clic en ciertos botones (botones cuya propiedad CommandName presenta valores como "Delete", "Update" y "Page"). Al utilizar uno de estos botones, se debería considerar la posibilidad de controlar uno de los eventos especializados proporcionados por el control (como RowDeleted o RowDeleting).

Cuando se crea un delegado GridViewCommandEventHandler, se identifica el método que controlará el evento. Para asociar el evento al controlador del evento, se debe agregar al evento una instancia del delegado. Siempre que se produzca el evento, se llamará al controlador del evento, a menos que se elimine el delegado. Para obtener más información sobre los delegados de los controladores de eventos, vea Eventos y delegados.

Ejemplo

El siguiente ejemplo muestra cómo agregar un delegado GridViewCommandEventHandler mediante programación al evento RowCommand de un control GridView.

Visual Basic

<%@ 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">

  Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)

    ' Create a new GridView object.
    Dim customersGridView As New GridView()

    ' Set the GridView object's properties.
    customersGridView.ID = "CustomersGridView"
    customersGridView.DataSourceID = "CustomersSource"
    customersGridView.AutoGenerateColumns = False

    ' Dynamically create the columns for the GridView control.
    Dim addColumn As New ButtonField()
    addColumn.CommandName = "Add"
    addColumn.Text = "Add"
    addColumn.ButtonType = ButtonType.Link

    Dim companyNameColumn As New BoundField()
    companyNameColumn.DataField = "CompanyName"
    companyNameColumn.HeaderText = "Company Name"

    Dim cityColumn As New BoundField()
    cityColumn.DataField = "City"
    cityColumn.HeaderText = "City"

    ' Add the columns to the Columns collection
    ' of the GridView control.
    customersGridView.Columns.Add(addColumn)
    customersGridView.Columns.Add(companyNameColumn)
    customersGridView.Columns.Add(cityColumn)

    ' Programmatically register the event handling methods.
    AddHandler customersGridView.RowCommand, AddressOf CustomersGridView_RowCommand
    AddHandler customersGridView.RowCreated, AddressOf CustomersGridView_RowCreated

    ' Add the GridView object to the Controls collection
    ' of the PlaceHolder control.
    GridViewPlaceHolder.Controls.Add(customersGridView)

  End Sub

  Sub CustomersGridView_RowCommand(ByVal sender As Object, ByVal e As GridViewCommandEventArgs)
  
    ' If multiple ButtonField columns are used, use the
    ' CommandName property to determine which button was clicked.
    If e.CommandName = "Add" Then
    
      ' Convert the row index stored in the CommandArgument
      ' property to an Integer.
      Dim index As Integer = Convert.ToInt32(e.CommandArgument)

      ' Retrieve the row that contains the button clicked
      ' by the user from the Rows collection. Use the
      ' CommandSource property to access the GridView control.
      Dim customersGridView As GridView = CType(e.CommandSource, GridView)
      Dim row As GridViewRow = customersGridView.Rows(index)

      ' Create a new ListItem object for the customer in the row.
      Dim item As New ListItem()
      item.Text = Server.HtmlDecode(row.Cells(1).Text) + " " + Server.HtmlDecode(row.Cells(2).Text)

      ' If the author is not already in the ListBox, add the ListItem
      ' object to the Items collection of a ListBox control.
      If Not CustomersListBox.Items.Contains(item) Then
      
        CustomersListBox.Items.Add(item)
        
      End If
    End If
        
  End Sub

  Sub CustomersGridView_RowCreated(ByVal sender As Object, ByVal e As GridViewRowEventArgs)

    ' The GridViewCommandEventArgs class does not contain a
    ' property that indicates which row's command button was
    ' clicked. To identify which row was clicked, use the button's
    ' CommandArgument property by setting it to the row's index.
    If e.Row.RowType = DataControlRowType.DataRow Then

      ' Retrieve the LinkButton control from the first column.
      Dim addButton As LinkButton = CType(e.Row.Cells(0).Controls(0), LinkButton)

      ' Set the LinkButton's CommandArgument property with the
      ' row's index.
      addButton.CommandArgument = e.Row.RowIndex.ToString()
      
    End If

  End Sub

</script>

<html  >
  <head runat="server">
    <title>GridViewCommandEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <h3>GridViewCommandEventHandler Example</h3>

      <table width="100%">
        <tr>
          <td style="width:50%">
            <asp:placeholder id="GridViewPlaceHolder"
              runat="Server"/>
          </td>

          <td style="vertical-align:top; width:50%">
             Customers: <br/>
             <asp:listbox id="CustomersListBox"
               runat="server"/>
          </td>
        </tr>
      </table>

      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="CustomersSource"
        selectcommand="Select [CustomerID], [CompanyName], [City] From [Customers]"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>

    </form>
  </body>
</html>

<%@ 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">

  void Page_Load(Object sender, EventArgs e)
  {

    // Create a new GridView object.
    GridView customersGridView = new GridView();

    // Set the GridView object's properties.
    customersGridView.ID = "CustomersGridView";
    customersGridView.DataSourceID = "CustomersSource";
    customersGridView.AutoGenerateColumns = false;

    // Dynamically create the columns for the GridView control.
    ButtonField addColumn = new ButtonField();
    addColumn.CommandName = "Add";
    addColumn.Text = "Add";
    addColumn.ButtonType = ButtonType.Link;

    BoundField companyNameColumn = new BoundField();
    companyNameColumn.DataField = "CompanyName";
    companyNameColumn.HeaderText = "Company Name";

    BoundField cityColumn = new BoundField();
    cityColumn.DataField = "City";
    cityColumn.HeaderText = "City";

    // Add the columns to the Columns collection
    // of the GridView control.
    customersGridView.Columns.Add(addColumn);
    customersGridView.Columns.Add(companyNameColumn);
    customersGridView.Columns.Add(cityColumn);

    // Programmatically register the event handling methods.
    customersGridView.RowCommand += new GridViewCommandEventHandler(this.CustomersGridView_RowCommand);
    customersGridView.RowCreated += new GridViewRowEventHandler(this.CustomersGridView_RowCreated);

    // Add the GridView object to the Controls collection
    // of the PlaceHolder control.
    GridViewPlaceHolder.Controls.Add(customersGridView);

  }

  void CustomersGridView_RowCommand(Object sender, GridViewCommandEventArgs e)
  {
    // If multiple ButtonField columns are used, use the
    // CommandName property to determine which button was clicked.
    if(e.CommandName=="Add")
    {
      // Convert the row index stored in the CommandArgument
      // property to an Integer.
      int index = Convert.ToInt32(e.CommandArgument);

      // Retrieve the row that contains the button clicked
      // by the user from the Rows collection. Use the
      // CommandSource property to access the GridView control.
      GridView customersGridView = (GridView)e.CommandSource;
      GridViewRow row = customersGridView.Rows[index];

      // Create a new ListItem object for the customer in the row.
      ListItem item = new ListItem();
      item.Text = Server.HtmlDecode(row.Cells[1].Text) + " " + Server.HtmlDecode(row.Cells[2].Text);

      // If the author is not already in the ListBox, add the ListItem
      // object to the Items collection of a ListBox control.
      if(!CustomersListBox.Items.Contains(item))
      {
        CustomersListBox.Items.Add(item);
      }
    }
  }

  void CustomersGridView_RowCreated(Object sender, GridViewRowEventArgs e)
  {

    // The GridViewCommandEventArgs class does not contain a
    // property that indicates which row's command button was
    // clicked. To identify which row was clicked, use the button's
    // CommandArgument property by setting it to the row's index.
    if(e.Row.RowType == DataControlRowType.DataRow)
    {
      // Retrieve the LinkButton control from the first column.
      LinkButton addButton = (LinkButton)e.Row.Cells[0].Controls[0];

      // Set the LinkButton's CommandArgument property with the
      // row's index.
      addButton.CommandArgument = e.Row.RowIndex.ToString();
    }

  }

</script>

<html  >
  <head runat="server">
    <title>GridViewCommandEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <h3>GridViewCommandEventHandler Example</h3>

      <table width="100%">
        <tr>
          <td style="width:50%">
            <asp:placeholder id="GridViewPlaceHolder"
              runat="Server"/>
          </td>

          <td style="vertical-align:top; width:50%">
             Customers: <br/>
             <asp:listbox id="CustomersListBox"
               runat="server"/>
          </td>
        </tr>
      </table>

      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="CustomersSource"
        selectcommand="Select [CustomerID], [CompanyName], [City] From [Customers]"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>

    </form>
  </body>
</html>

El siguiente ejemplo muestra cómo agregar un delegado GridViewCommandEventHandler mediante declaración al evento RowCommand de un control GridView.

Visual Basic

<%@ 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">

  Sub CustomersGridView_RowCommand(ByVal sender As Object, ByVal e As GridViewCommandEventArgs)

    ' If multiple buttons are used in a GridView control, use the
    ' CommandName property to determine which button was clicked.
    If e.CommandName = "Add" Then
    
      ' Convert the row index stored in the CommandArgument
      ' property to an Integer.
      Dim index As Integer = Convert.ToInt32(e.CommandArgument)
            
      ' Retrieve the row that contains the button clicked 
      ' by the user from the Rows collection.
      Dim row As GridViewRow = CustomersGridView.Rows(index)
            
      ' Create a new ListItem object for the customer in the row.     
      Dim item As New ListItem()
      item.Text = Server.HtmlDecode(row.Cells(2).Text)
            
      ' If the customer is not already in the ListBox, add the ListItem 
      ' object to the Items collection of the ListBox control. 
      If Not CustomersListBox.Items.Contains(item) Then
      
        CustomersListBox.Items.Add(item)
        
      End If
      
    End If
    
  End Sub

  Sub CustomersGridView_RowCreated(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
    
    ' The GridViewCommandEventArgs class does not contain a 
    ' property that indicates which row's command button was
    ' clicked. To identify which row's button was clicked, use 
    ' the button's CommandArgument property by setting it to the 
    ' row's index.
    If e.Row.RowType = DataControlRowType.DataRow Then
    
      ' Retrieve the LinkButton control from the first column.
      Dim addButton As LinkButton = CType(e.Row.Cells(0).Controls(0), LinkButton)
          
      ' Set the LinkButton's CommandArgument property with the
      ' row's index.
      addButton.CommandArgument = e.Row.RowIndex.ToString()
      
    End If

  End Sub
    
</script>

<html  >
  <head runat="server">
    <title>GridView RowCommand Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridView RowCommand Example</h3>
            
      <table width="100%">         
        <tr>                
          <td style="width:50%">
                    
            <asp:gridview id="CustomersGridView" 
              datasourceid="CustomersSource"
              allowpaging="true" 
              autogeneratecolumns="false"
              onrowcommand="CustomersGridView_RowCommand"
              onrowcreated="CustomersGridView_RowCreated"  
              runat="server">
                
              <columns>
                <asp:buttonfield buttontype="Link" 
                  commandname="Add" 
                  text="Add"/>
                <asp:boundfield datafield="CustomerID" 
                  headertext="Customer ID"/>
                <asp:boundfield datafield="CompanyName" 
                  headertext="Company Name"/> 
                <asp:boundfield datafield="City" 
                  headertext="City"/>         
              </columns>
                
            </asp:gridview>
                    
          </td>
                    
          <td style="vertical-align:top; width:50%">
                    
            Customers: <br/>
            <asp:listbox id="CustomersListBox"
              runat="server"/> 
                    
          </td>  
        </tr>      
      </table>
            
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="CustomersSource"
        selectcommand="Select [CustomerID], [CompanyName], [City] From [Customers]"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
            
    </form>
  </body>
</html>

<%@ 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">

  void CustomersGridView_RowCommand(Object sender, GridViewCommandEventArgs e)
  {
    // If multiple buttons are used in a GridView control, use the
    // CommandName property to determine which button was clicked.
    if(e.CommandName=="Add")
    {
      // Convert the row index stored in the CommandArgument
      // property to an Integer.
      int index = Convert.ToInt32(e.CommandArgument);
            
      // Retrieve the row that contains the button clicked 
      // by the user from the Rows collection.
      GridViewRow row = CustomersGridView.Rows[index];
            
      // Create a new ListItem object for the customer in the row.     
      ListItem item = new ListItem();
      item.Text = Server.HtmlDecode(row.Cells[2].Text);
            
      // If the customer is not already in the ListBox, add the ListItem 
      // object to the Items collection of the ListBox control. 
      if (!CustomersListBox.Items.Contains(item))
      {
        CustomersListBox.Items.Add(item);
      }           
    }
  }

  void CustomersGridView_RowCreated(Object sender, GridViewRowEventArgs e)
  {
    
    // The GridViewCommandEventArgs class does not contain a 
    // property that indicates which row's command button was
    // clicked. To identify which row's button was clicked, use 
    // the button's CommandArgument property by setting it to the 
    // row's index.
    if(e.Row.RowType == DataControlRowType.DataRow)
    {
      // Retrieve the LinkButton control from the first column.
      LinkButton addButton = (LinkButton)e.Row.Cells[0].Controls[0];
          
      // Set the LinkButton's CommandArgument property with the
      // row's index.
      addButton.CommandArgument = e.Row.RowIndex.ToString();
    }

  }
    
</script>

<html  >
  <head runat="server">
    <title>GridView RowCommand Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridView RowCommand Example</h3>
            
      <table width="100%">         
        <tr>                
          <td style="width:50%">
                    
            <asp:gridview id="CustomersGridView" 
              datasourceid="CustomersSource"
              allowpaging="true" 
              autogeneratecolumns="false"
              onrowcommand="CustomersGridView_RowCommand"
              onrowcreated="CustomersGridView_RowCreated"  
              runat="server">
                
              <columns>
                <asp:buttonfield buttontype="Link" 
                  commandname="Add" 
                  text="Add"/>
                <asp:boundfield datafield="CustomerID" 
                  headertext="Customer ID"/>
                <asp:boundfield datafield="CompanyName" 
                  headertext="Company Name"/> 
                <asp:boundfield datafield="City" 
                  headertext="City"/>         
              </columns>
                
            </asp:gridview>
                    
          </td>
                    
          <td style="vertical-align:top; width:50%">
                    
            Customers: <br/>
            <asp:listbox id="CustomersListBox"
              runat="server"/> 
                    
          </td>  
        </tr>      
      </table>
            
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="CustomersSource"
        selectcommand="Select [CustomerID], [CompanyName], [City] From [Customers]"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
            
    </form>
  </body>
</html>

Plataformas

Windows 98, Windows 2000 Service Pack 4, Windows CE, Windows Millennium, Windows Mobile para Pocket PC, Windows Mobile para Smartphone, Windows Server 2003, Windows XP Media Center, Windows XP Professional x64, Windows XP SP2, Windows XP Starter

Microsoft .NET Framework 3.0 es compatible con Windows Vista, Microsoft Windows XP SP2 y Windows Server 2003 SP1.

Información de versión

.NET Framework

Compatible con: 3.0, 2.0

Vea también

Referencia

System.Web.UI.WebControls (Espacio de nombres)
GridView
GridViewCommandEventArgs
GridView.RowCommand (Evento)
OnRowCommand

Otros recursos

Eventos y delegados

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