Partager via


GridViewSelectEventHandler Délégué

Définition

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

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

Paramètres

sender
Object

Source de l'événement.

e
GridViewSelectEventArgs

Objet GridViewSelectEventArgs qui contient les données d'événement.

Exemples

L’exemple suivant montre comment ajouter par programmation un GridViewSelectEventHandler délégué à l’événement SelectedIndexChanging 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 authorGridView = new GridView();
         
        // Set the GridView object's properties.
        authorGridView.ID = "AuthorGridView";
        authorGridView.DataSourceID = "AuthorsSqlDataSource"; 
        authorGridView.AutoGenerateColumns = true;
        authorGridView.AutoGenerateSelectButton = true;
        authorGridView.AllowPaging = true; 
        authorGridView.SelectedIndex = 1;
        authorGridView.SelectedRowStyle.BackColor = System.Drawing.Color.LightCyan;
        authorGridView.SelectedRowStyle.ForeColor = System.Drawing.Color.DarkBlue;
        authorGridView.SelectedRowStyle.Font.Bold = true;
        
        // Programmatically register the event-handling methods.
        authorGridView.SelectedIndexChanged += new EventHandler(this.AuthorsGridView_SelectedIndexChanged);
        authorGridView.SelectedIndexChanging += new GridViewSelectEventHandler(this.AuthorsGridView_SelectedIndexChanging);
        
        // Add the GridView object to the Controls collection
        // of the PlaceHolder control.
        GridViewPlaceHolder.Controls.Add(authorGridView);
        
    }
    
    void AuthorsGridView_SelectedIndexChanged(Object sender, EventArgs e)
    {
    
        // Get the currently selected row using the SelectedRow property.
        GridView AuthorsGridView = (GridView)sender;
        GridViewRow row = AuthorsGridView.SelectedRow;
        
        // Display the author's name from the selected row.
        // In this example, the second and third columns contain
        // the author's last and first name, respectively.
        Message.Text = "You selected " + row.Cells[2].Text +
            " " + row.Cells[1].Text + ".";
    
    }
    
    void AuthorsGridView_SelectedIndexChanging(Object sender, GridViewSelectEventArgs e)
    {
        
        // Get the currently selected row. Because the SelectedIndexChanging event
        // occurs before the select operation in the GridView control, the
        // SelectedRow property cannot be used. Instead, use the Rows collection
        // and the NewSelectedIndex property of the e argument passed to this 
        // event handler.
        GridView AuthorsGridView = (GridView)sender;
        GridViewRow row = AuthorsGridView.Rows[e.NewSelectedIndex];
        
        // If the user selects an author with the last name White,
        // cancel the selection operation and display an error message.
        if(row.Cells[1].Text == "White")
        {
        
            e.Cancel = true;
            Message.Text = "You cannot select " + row.Cells[2].Text +
            " " + row.Cells[1].Text + ".";
        
        }
    
    }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
    <head runat="server">
    <title>GridViewSelectEventHandler Example</title>
</head>
<body>
        <form id="form1" runat="server">
        
            <h3>GridViewSelectEventHandler Example</h3>
            
            <asp:placeholder id="GridViewPlaceHolder"
                runat="Server"/>
            
            <!-- This example uses Microsoft SQL Server and connects -->
            <!-- to the Pubs sample database.                         -->
            <asp:sqldatasource id="AuthorsSqlDataSource"  
                selectcommand="SELECT [au_lname], [au_fname], [address], [city], [state], [zip], [contract] FROM [authors]"
                connectionstring="server=localhost;database=pubs;integrated security=SSPI"
                runat="server">
            </asp:sqldatasource>
            
            <br/>
            
            <asp:label id="Message"
                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 authorGridView As GridView = New GridView
         
        ' Set the GridView object's properties.
        authorGridView.ID = "AuthorGridView"
        authorGridView.DataSourceID = "AuthorsSqlDataSource"
        authorGridView.AutoGenerateColumns = True
        authorGridView.AutoGenerateSelectButton = True
        authorGridView.AllowPaging = True
        authorGridView.SelectedIndex = 1
        authorGridView.SelectedRowStyle.BackColor = System.Drawing.Color.LightCyan
        authorGridView.SelectedRowStyle.ForeColor = System.Drawing.Color.DarkBlue
        authorGridView.SelectedRowStyle.Font.Bold = True
        
        ' Programmatically register the event-handling methods.
        AddHandler authorGridView.SelectedIndexChanged, AddressOf AuthorsGridView_SelectedIndexChanged
        AddHandler authorGridView.SelectedIndexChanging, AddressOf AuthorsGridView_SelectedIndexChanging
        
        ' Add the GridView object to the Controls collection
        ' of the PlaceHolder control.
        GridViewPlaceHolder.Controls.Add(authorGridView)
        
    End Sub
    
    Sub AuthorsGridView_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)

        ' Get the currently selected row using the SelectedRow property.
        Dim AuthorsGridView As GridView = CType(sender, GridView)
        Dim row As GridViewRow = AuthorsGridView.SelectedRow
        
        ' Display the author's name from the selected row.
        ' In this example, the second and third columns contain
        ' the author's last and first name, respectively.
        Message.Text = "You selected " & row.Cells(2).Text & _
            " " & row.Cells(1).Text & "."
    
    End Sub
    
    Sub AuthorsGridView_SelectedIndexChanging(ByVal sender As Object, ByVal e As GridViewSelectEventArgs)
        
        ' Get the currently selected row. Because the SelectedIndexChanging event
        ' occurs before the select operation in the GridView control, the
        ' SelectedRow property cannot be used. Instead, use the Rows collection
        ' and the NewSelectedIndex property of the e argument passed to this 
        ' event handler.
        Dim AuthorsGridView As GridView = CType(sender, GridView)
        Dim row As GridViewRow = AuthorsGridView.Rows(e.NewSelectedIndex)
        
        ' If the user selects an author with the last name White,
        ' cancel the selection operation and display an error message.
        If row.Cells(1).Text = "White"
        
            e.Cancel = true
            Message.Text = "You cannot select " & row.Cells(2).Text & _
            " " & row.Cells(1).Text & "."
        
        End If
    
    End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
    <head runat="server">
    <title>GridViewSelectEventHandler Example</title>
</head>
<body>
        <form id="form1" runat="server">
        
            <h3>GridViewSelectEventHandler Example</h3>
            
            <asp:placeholder id="GridViewPlaceHolder"
                runat="Server"/>
            
            <!-- This example uses Microsoft SQL Server and connects -->
            <!-- to the Pubs sample database.                         -->
            <asp:sqldatasource id="AuthorsSqlDataSource"  
                selectcommand="SELECT [au_lname], [au_fname], [address], [city], [state], [zip], [contract] FROM [authors]"
                connectionstring="server=localhost;database=pubs;integrated security=SSPI"
                runat="server">
            </asp:sqldatasource>
            
            <br/>
            
            <asp:label id="Message"
                runat="server"/>
            
        </form>
    </body>
</html>

L’exemple suivant montre comment ajouter de manière déclarative un GridViewSelectEventHandler délégué à l’événement SelectedIndexChanging 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 CustomersGridView_SelectedIndexChanged(Object sender, EventArgs e)
  {
    // Get the currently selected row using the SelectedRow property.
    GridViewRow row = CustomersGridView.SelectedRow;
        
    // Display the first name from the selected row.
    // In this example, the third column (index 2) contains
    // the first name.
    MessageLabel.Text = "You selected " + row.Cells[2].Text + ".";
  }

  void CustomersGridView_SelectedIndexChanging(Object sender, GridViewSelectEventArgs e)
  {
    // Get the currently selected row. Because the SelectedIndexChanging event
    // occurs before the select operation in the GridView control, the
    // SelectedRow property cannot be used. Instead, use the Rows collection
    // and the NewSelectedIndex property of the e argument passed to this 
    // event handler.
    GridViewRow row = CustomersGridView.Rows[e.NewSelectedIndex];

    // You can cancel the select operation by using the Cancel
    // property. For this example, if the user selects a customer with 
    // the ID "ANATR", the select operation is canceled and an error message
    // is displayed.
    if (row.Cells[1].Text == "ANATR")
    {
      e.Cancel = true;
      MessageLabel.Text = "You cannot select " + row.Cells[2].Text + "."; 
    }
  }

</script>

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

     <asp:gridview id="CustomersGridView" 
       datasourceid="CustomersSource" 
       autogeneratecolumns="False"
       autogenerateselectbutton="True"
       selectedindex="1"
       onselectedindexchanged="CustomersGridView_SelectedIndexChanged"
       onselectedindexchanging="CustomersGridView_SelectedIndexChanging"   
       runat="server" DataKeyNames="CustomerID">
                
         <Columns>
             <asp:BoundField DataField="CustomerID" 
                 HeaderText="CustomerID" 
                 InsertVisible="False" ReadOnly="True" 
                 SortExpression="CustomerID" />
             <asp:BoundField DataField="FirstName" 
                 HeaderText="FirstName" 
                 SortExpression="FirstName" />
             <asp:BoundField DataField="MiddleName" 
                 HeaderText="MiddleName" 
                 SortExpression="MiddleName" />
             <asp:BoundField DataField="LastName" 
                 HeaderText="LastName" 
                 SortExpression="LastName" />
             <asp:BoundField DataField="Phone" 
                 HeaderText="Phone" 
                 SortExpression="Phone" />
         </Columns>
                
       <selectedrowstyle backcolor="LightCyan"
         forecolor="DarkBlue"
         font-bold="true"/>  
                
     </asp:gridview>
            
      <br/>
            
      <asp:label id="MessageLabel"
        forecolor="Red"
        runat="server"/>
            
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the 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, FirstName, MiddleName, LastName, Phone FROM SalesLT.Customer"
        connectionstring="<%$ ConnectionStrings:AdventureWorksLTConnectionString %>" 
        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 CustomersGridView_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
        
    ' Get the currently selected row using the SelectedRow property.
    Dim row As GridViewRow = CustomersGridView.SelectedRow
        
    ' Display the first name from the selected row.
    ' In this example, the third column (index 2) contains
    ' the first name.
    MessageLabel.Text = "You selected " & row.Cells(2).Text & "."
  End Sub

  Sub CustomersGridView_SelectedIndexChanging(ByVal sender As Object, ByVal e As GridViewSelectEventArgs)
        
    ' Get the currently selected row. Because the SelectedIndexChanging event
    ' occurs before the select operation in the GridView control, the
    ' SelectedRow property cannot be used. Instead, use the Rows collection
    ' and the NewSelectedIndex property of the e argument passed to this 
    ' event handler.
    Dim row As GridViewRow = CustomersGridView.Rows(e.NewSelectedIndex)

    ' You can cancel the select operation by using the Cancel
    ' property. For this example, if the user selects a customer with 
    ' the ID "ANATR", the select operation is canceled and an error message
    ' is displayed.
    If row.Cells(1).Text = "ANATR" Then
        e.Cancel = True
        MessageLabel.Text = "You cannot select " + row.Cells(2).Text & "."
    End If
    
  End Sub

</script>

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

     <asp:gridview id="CustomersGridView" 
       datasourceid="CustomersSource" 
       autogeneratecolumns="False"
       autogenerateselectbutton="True"
       selectedindex="1"
       onselectedindexchanged="CustomersGridView_SelectedIndexChanged"
       onselectedindexchanging="CustomersGridView_SelectedIndexChanging"   
       runat="server" DataKeyNames="CustomerID">
                
         <Columns>
             <asp:BoundField DataField="CustomerID" 
                 HeaderText="CustomerID" 
                 InsertVisible="False" ReadOnly="True" 
                 SortExpression="CustomerID" />
             <asp:BoundField DataField="FirstName" 
                 HeaderText="FirstName" 
                 SortExpression="FirstName" />
             <asp:BoundField DataField="MiddleName" 
                 HeaderText="MiddleName" 
                 SortExpression="MiddleName" />
             <asp:BoundField DataField="LastName" 
                 HeaderText="LastName" 
                 SortExpression="LastName" />
             <asp:BoundField DataField="Phone" 
                 HeaderText="Phone" 
                 SortExpression="Phone" />
         </Columns>
                
       <selectedrowstyle backcolor="LightCyan"
         forecolor="DarkBlue"
         font-bold="true"/>  
                
     </asp:gridview>
            
      <br/>
            
      <asp:label id="MessageLabel"
        forecolor="Red"
        runat="server"/>
            
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the 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, FirstName, MiddleName, LastName, Phone FROM SalesLT.Customer"
        connectionstring="<%$ ConnectionStrings:AdventureWorksLTConnectionString %>" 
        runat="server"/>
            
    </form>

  </body>
</html>

Remarques

L’événement SelectedIndexChanging est déclenché lorsqu’un bouton Sélectionner (un bouton dont la CommandName propriété est définie sur « Sélectionner ») est cliqué, mais avant que le GridView contrôle ne gère l’opération de sélection. Cela vous permet de fournir une méthode de gestion des événements qui effectue une routine personnalisée, telle que l’annulation de l’opération de sélection, chaque fois que cet événement se produit.

Lorsque vous créez un délégué GridViewSelectEventHandler, 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