GridViewCommandEventHandler Délégué

  • Référence

Définition

Espace de noms:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Représente la méthode qui gère l'événement RowCommand d'un contrôle GridView.

public delegate void GridViewCommandEventHandler(System::Object ^ sender, GridViewCommandEventArgs ^ e);
public delegate void GridViewCommandEventHandler(object sender, GridViewCommandEventArgs e);
type GridViewCommandEventHandler = delegate of obj * GridViewCommandEventArgs -> unit
Public Delegate Sub GridViewCommandEventHandler(sender As Object, e As GridViewCommandEventArgs)

Paramètres

sender
Object

Source de l'événement.

e
GridViewCommandEventArgs

Objet GridViewCommandEventArgs qui contient les données d'événement.

Exemples

L’exemple suivant montre comment ajouter par programmation un GridViewCommandEventHandler délégué à l’événement RowCommand d’un GridView contrôle.


<%@ 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 xmlns="http://www.w3.org/1999/xhtml" >
  <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="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 xmlns="http://www.w3.org/1999/xhtml" >
  <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>

L’exemple suivant montre comment ajouter de manière déclarative un GridViewCommandEventHandler délégué à l’événement RowCommand d’un GridView contrôle.


<%@ 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 ContactsGridView_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 = ContactsGridView.Rows[index];

      // Create a new ListItem object for the contact in the row.     
      ListItem item = new ListItem();
      item.Text = Server.HtmlDecode(row.Cells[2].Text) + " " +
        Server.HtmlDecode(row.Cells[3].Text);

      // If the contact is not already in the ListBox, add the ListItem 
      // object to the Items collection of the ListBox control. 
      if (!ContactsListBox.Items.Contains(item))
      {
        ContactsListBox.Items.Add(item);
      }
    }
  }    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <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="ContactsGridView" 
              datasourceid="ContactsSource"
              allowpaging="true" 
              autogeneratecolumns="false"
              onrowcommand="ContactsGridView_RowCommand"
              runat="server">

              <columns>
                <asp:buttonfield buttontype="Link" 
                  commandname="Add" 
                  text="Add"/>
                <asp:boundfield datafield="ContactID" 
                  headertext="Contact ID"/>
                <asp:boundfield datafield="FirstName" 
                  headertext="First Name"/> 
                <asp:boundfield datafield="LastName" 
                  headertext="Last Name"/>
              </columns>

            </asp:gridview>

          </td>

          <td style="vertical-align:top; width:50%">

            Contacts: <br/>
            <asp:listbox id="ContactsListBox"
              runat="server" Height="200px" Width="200px"/>

          </td>
        </tr>
      </table>

      <!-- 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="ContactsSource"
        selectcommand="Select [ContactID], [FirstName], [LastName] From Person.Contact"
        connectionstring="<%$ ConnectionStrings:AdventureWorks_DataConnectionString%>" 
        runat="server"/>

    </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">

  Sub ContactsGridView_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 = ContactsGridView.Rows(index)
            
      ' Create a new ListItem object for the contact in the row.     
      Dim item As New ListItem()
      item.Text = Server.HtmlDecode(row.Cells(2).Text) & " " & _
        Server.HtmlDecode(row.Cells(3).Text)
            
      ' If the contact is not already in the ListBox, add the ListItem 
      ' object to the Items collection of the ListBox control. 
      If Not ContactsListBox.Items.Contains(item) Then
      
        ContactsListBox.Items.Add(item)
        
      End If
      
    End If
    
  End Sub
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head id="Head1" 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="ContactsGridView" 
              datasourceid="ContactsSource"
              allowpaging="true" 
              autogeneratecolumns="false"
              onrowcommand="ContactsGridView_RowCommand"
              runat="server">

              <columns>
                <asp:buttonfield buttontype="Link" 
                  commandname="Add" 
                  text="Add"/>
                <asp:boundfield datafield="ContactID" 
                  headertext="Contact ID"/>
                <asp:boundfield datafield="FirstName" 
                  headertext="First Name"/> 
                <asp:boundfield datafield="LastName" 
                  headertext="Last Name"/>
              </columns>

            </asp:gridview>

          </td>

          <td style="vertical-align:top; width:50%">

            Contacts: <br/>
            <asp:listbox id="ContactsListBox"
              runat="server" Height="200px" Width="200px"/>

          </td>
        </tr>
      </table>

      <!-- 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="ContactsSource"
        selectcommand="Select [ContactID], [FirstName], [LastName] From Person.Contact"
        connectionstring="<%$ ConnectionStrings:AdventureWorks_DataConnectionString%>" 
        runat="server"/>

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

Remarques

L’événement RowCommand est déclenché lorsqu’un bouton du GridView contrôle est cliqué. Cela vous permet de fournir une méthode de gestion des événements qui effectue une routine personnalisée chaque fois que cet événement se produit.

Notes

Le GridView contrôle déclenche également d’autres événements spécialisés lorsque vous cliquez sur certains boutons (boutons dont la CommandName propriété est définie sur « Supprimer », « Mettre à jour » et « Page », par exemple). Lorsque vous utilisez l’un de ces boutons, vous devez envisager de gérer l’un des événements spécialisés fournis par le contrôle (tels que RowDeleted ou RowDeleting).

Lorsque vous créez un délégué GridViewCommandEventHandler, vous identifiez la méthode qui gérera l'événement. Pour associer l'événement au gestionnaire d'événements, ajoutez une instance du délégué à l'événement. Le gestionnaire d'événements est appelé chaque fois qu'un événement se produit, sauf si vous supprimez le délégué. Pour plus d’informations sur les délégués du gestionnaire d’événements, consultez Gestion et levée d’événements.

Méthodes d’extension

GetMethodInfo(Delegate)

Obtient un objet qui représente la méthode représentée par le délégué spécifié.

S’applique à

Voir aussi