DetailsView.DataKey Proprietà

  • Riferimento

Definizione

Spazio dei nomi:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Ottiene un oggetto DataKey che rappresenta la chiave primaria del record visualizzato.

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

Valore della proprietà

DataKey

Oggetto DataKey che rappresenta la chiave primaria del record visualizzato.

Attributi
BrowsableAttribute

Esempio

Nell'esempio di codice seguente viene illustrato come usare la proprietà per determinare il DataKey campo chiave e il valore corrispondente per il record corrente.


<%@ 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 CustomerDetailView_ItemUpdated(Object sender, 
    DetailsViewUpdatedEventArgs e)
  {
  
    // Create a dictionary that contains the key fields and values using
    // the AllValues method of the DataKey object contained in the DataKey 
    // property.
    IOrderedDictionary keyList = CustomerDetailView.DataKey.Values;

    // Get the ArrayList objects that represent the key fields and values.
    ArrayList keys = (ArrayList)keyList.Keys;
    ArrayList values = (ArrayList)keyList.Values;

    // Get the key field and value for the current record. 
    String keyField = keys[0].ToString();
    String keyValue = values[0].ToString();
    
    // Log the update operation using the key field and value.
    LogUpdate(keyField, keyValue);

  }

  void LogUpdate(String keyField, String keyValue)
  {
    // Insert code to log the update operation.
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>DetailsView DataKey Example</title>
</head>
<body>
    <form id="Form1" runat="server">
        
      <h3>DetailsView DataKey Example</h3>
                
        <asp:detailsview id="CustomerDetailView"
          datasourceid="DetailsViewSource"
          datakeynames="CustomerID"
          autogeneraterows="true"
          autogenerateeditbutton="true" 
          allowpaging="true"
          onitemupdated="CustomerDetailView_ItemUpdated" 
          runat="server">
               
          <headerstyle backcolor="Navy"
            forecolor="White"/>
                    
        </asp:detailsview>
        
        <!-- 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="DetailsViewSource" runat="server" 
          ConnectionString=
            "<%$ ConnectionStrings:NorthWindConnectionString%>"
                    InsertCommand="INSERT INTO [Customers]([CustomerID], 
            [CompanyName], [Address], [City], [PostalCode], [Country]) 
            VALUES (@CustomerID, @CompanyName, @Address, @City, 
            @PostalCode, @Country)"
          SelectCommand="Select [CustomerID], [CompanyName], 
            [Address], [City], [PostalCode], [Country] From [Customers]"
          UpdateCommand="UPDATE [Customers] SET 
            [CompanyName] = @CompanyName, 
            [Address] = @Address, [City] = @City,
            [PostalCode] = @PostalCode, [Country] = @Country
            WHERE [CustomerID] = @CustomerID">
        </asp:SqlDataSource>
    </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 CustomerDetailView_ItemUpdated(ByVal sender As Object, _
        ByVal e As DetailsViewUpdatedEventArgs)
    
        ' Create a dictionary that contains the key fields and values 
        ' using the AllValues method of the DataKey object contained 
        ' in the DataKey property.
        
        Dim keyList As IOrderedDictionary = _
            CustomerDetailsView.DataKey.Values

        ' Get the ArrayList objects that represent the key fields 
        ' and values.
        Dim keys As ArrayList = CType(keyList.Keys, ArrayList)
        Dim values As ArrayList = CType(keyList.Values, ArrayList)

        ' Get the key field and value for the current record. 
        Dim keyField As String = keys(0).ToString()
        Dim keyValue As String = values(0).ToString()
    
        ' Log the update operation using the key field and value.
        LogUpdate(keyField, keyValue)

    End Sub

    Sub LogUpdate(ByVal keyField As String, ByVal keyValue As String)
  
        ' Insert code to log the update operation.
  
    End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>
            DetailsView DataKey Example</title>
</head>
<body>
    <form id="Form1" runat="server">
        <h3>
            DetailsView DataKey Example</h3>
        <asp:DetailsView ID="CustomerDetailsView" 
          DataSourceID="DetailsViewSource" 
          DataKeyNames="CustomerID"
          AutoGenerateRows="true" 
          AutoGenerateEditButton="true" 
          AllowPaging="true" 
          OnItemUpdated="CustomerDetailView_ItemUpdated"
          runat="server">
          
          <HeaderStyle BackColor="Navy" ForeColor="White" />
        </asp:DetailsView>

        <!-- 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="DetailsViewSource" runat="server" 
          ConnectionString=
            "<%$ ConnectionStrings:NorthWindConnectionString%>"
          InsertCommand="INSERT INTO [Customers]([CustomerID],
            [CompanyName], [Address], [City], [PostalCode], [Country]) 
            VALUES (@CustomerID, @CompanyName, @Address, @City, 
            @PostalCode, @Country)"
            SelectCommand="Select [CustomerID], [CompanyName], 
              [Address], [City], [PostalCode], [Country] 
              From [Customers]"
            UpdateCommand="UPDATE [Customers] SET [CompanyName] = @CompanyName, 
            [Address] = @Address, [City] = @City,
            [PostalCode] = @PostalCode, [Country] = @Country
            WHERE [CustomerID] = @CustomerID"></asp:SqlDataSource>
    </form>
</body>
</html>

Commenti

Quando la DataKeyNames proprietà è impostata, il DetailsView controllo crea automaticamente un DataKey oggetto che rappresenta il campo chiave o i campi per il record corrente. Utilizzare la DataKey proprietà per ottenere questo DataKey oggetto. Questa proprietà viene comunemente usata per ottenere le chiavi e i relativi valori corrispondenti per i campi specificati nella DataKeyNames proprietà.

Nota

Come collegamento è anche possibile usare la SelectedValue proprietà per determinare il valore del primo campo chiave elencato nella DataKeyNames proprietà.

Si applica a

Vedi anche