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

Esempi

Nell'esempio seguente viene illustrato come utilizzare la DataKeys proprietà per determinare il valore della chiave di dati della riga selezionata in GridView un controllo.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 DataKeyNames impostata la proprietà, il GridView controllo crea automaticamente un DataKey oggetto 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' DataKey oggetto contiene i valori del campo o dei campi specificati DataKeyNames nella proprietà.The DataKey object contains the values of the field or fields specified in the DataKeyNames property. Gli DataKey oggetti vengono quindi aggiunti alla DataKeys raccolta del controllo.The DataKey objects are then added to the control's DataKeys collection. Utilizzare la DataKeys proprietà per recuperare l' DataKey oggetto per una riga di dati GridView specifica nel controllo.Use the DataKeys property to retrieve the DataKey object for a specific data row in the GridView control.

Nota

È possibile utilizzare la SelectedDataKey proprietà per recuperare l' DataKey oggetto 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 SelectedValue proprietà 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.

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