GridView.DataKeys Proprietà

Definizione

Ottiene un insieme di oggetti DataKey che rappresentano il valore della chiave dati di ciascuna riga di un controllo GridView.Gets a collection of DataKey objects that represent the data key value of each row in a GridView control.

public:
 virtual property System::Web::UI::WebControls::DataKeyArray ^ DataKeys { System::Web::UI::WebControls::DataKeyArray ^ get(); };
[System.ComponentModel.Browsable(false)]
public virtual System.Web.UI.WebControls.DataKeyArray DataKeys { get; }
member this.DataKeys : System.Web.UI.WebControls.DataKeyArray
Public Overridable ReadOnly Property DataKeys As DataKeyArray

Valore della proprietà

Un oggetto DataKeyArray contenente la chiave dati di ciascuna riga di un controllo GridView.A DataKeyArray that contains the data key of each row in a GridView control.

Implementazioni

Attributi

Esempio

Nell'esempio seguente viene illustrato come utilizzare la proprietà DataKeys per determinare il valore della chiave di dati della riga selezionata in un controllo GridView.The following example demonstrates how to use the DataKeys property to determine the data key value of the selected row in a GridView control.


<%@ 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)
  {
    
    // Determine the index of the selected row.
    int index = CustomersGridView.SelectedIndex;
        
    // Display the primary key value of the selected row.
    Message.Text = "The primary key value of the selected row is " +
        CustomersGridView.DataKeys[index].Value.ToString() + ".";
    
  }

</script>

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

      <asp:label id="Message"
        forecolor="Red"
        runat="server"/>
               
      <br/><br/>

      <asp:gridview id="CustomersGridView" 
        datasourceid="CustomersSource" 
        autogeneratecolumns="true"
        emptydatatext="No data available." 
        autogenerateselectbutton="true"    
        datakeynames="CustomerID"
        onselectedindexchanged="CustomersGridView_SelectedIndexChanged"
        runat="server">
                
      </asp:gridview>
            
      <!-- 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], [Address], [City], [PostalCode], [Country] 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 CustomersGridView_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
      
    ' Determine the index of the selected row.
    Dim index As Integer = CustomersGridView.SelectedIndex
        
    ' Display the primary key value of the selected row.
    Message.Text = "The primary key value of the selected row is " & _
        CustomersGridView.DataKeys(index).Value.ToString() & "."
    
  End Sub

</script>

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

      <asp:label id="Message"
        forecolor="Red"
        runat="server"/>
               
      <br/><br/>

      <asp:gridview id="CustomersGridView" 
        datasourceid="CustomersSource" 
        autogeneratecolumns="true"
        emptydatatext="No data available." 
        autogenerateselectbutton="true"    
        datakeynames="CustomerID"
        onselectedindexchanged="CustomersGridView_SelectedIndexChanged"
        runat="server">
                
      </asp:gridview>
            
      <!-- 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], [Address], [City], [PostalCode], [Country] From [Customers]"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
        
    </form>
  </body>
</html>

Commenti

Quando viene impostata la proprietà DataKeyNames, il controllo GridView crea automaticamente un oggetto DataKey per ogni riga nel controllo.When the DataKeyNames property is set, the GridView control automatically creates a DataKey object for each row in the control. L'oggetto DataKey contiene i valori del campo o dei campi specificati nella proprietà DataKeyNames.The DataKey object contains the values of the field or fields specified in the DataKeyNames property. Gli oggetti DataKey vengono quindi aggiunti alla raccolta di DataKeys del controllo.The DataKey objects are then added to the control's DataKeys collection. Utilizzare la proprietà DataKeys per recuperare l'oggetto DataKey per una riga di dati specifica nel controllo GridView.Use the DataKeys property to retrieve the DataKey object for a specific data row in the GridView control.

Nota

È possibile utilizzare la proprietà SelectedDataKey per recuperare l'oggetto DataKey per la riga attualmente selezionata.You can use the SelectedDataKey property to retrieve the DataKey object for the currently selected row. È anche possibile usare la proprietà SelectedValue per recuperare direttamente il valore della chiave di dati per la riga attualmente selezionata.You can also use the SelectedValue property to retrieve the data key value for the currently selected row directly.

Si applica a

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