DetailsViewUpdatedEventArgs.OldValues Property
Gets a dictionary that contains the original field name/value pairs for the updated record.
Assembly: System.Web (in System.Web.dll)
Property Value
Type: System.Collections.Specialized.IOrderedDictionaryAn IOrderedDictionary that contains a dictionary of the original field name/value pairs for the updated record.
Use the OldValues property to access the original field values for the updated record. For example, you can use these values to keep a log of updated records.
The OldValues property returns an object that implements the IOrderedDictionary interface. The object contains DictionaryEntry objects that represent the fields of the updated record.
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As a shortcut, you can also use the indexer of the IOrderedDictionary object to access the field values directly. |
The following code example demonstrates how to use the OldValues property to access the original values of the non-key fields for the updated record.
<%@ 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 CustomerDetailsView_ItemUpdated(ByVal sender As Object, ByVal e As DetailsViewUpdatedEventArgs) ' Use the Exception property to determine whether an exception ' occurred during the insert operation. If e.Exception Is Nothing Then ' Use the Values property to get the value entered by ' the user for the CompanyName field. Dim keyFieldValue As String = e.Keys("CustomerID").ToString() ' Display a confirmation message. MessageLabel.Text = "Record " & keyFieldValue & _ " updated successfully. " ' Display the old and new values. DisplayValues(e) If e.AffectedRows = 1 Then MessageLabel.Text &= e.AffectedRows.ToString() & _ " record updated." Else MessageLabel.Text &= e.AffectedRows.ToString() & _ " records updated." End If Else ' Insert the code to handle the exception. MessageLabel.Text = e.Exception.Message ' Use the ExceptionHandled property to indicate that the ' exception is already handled. e.ExceptionHandled = True ' When an exception occurs, keep the DetailsView ' control in edit mode. e.KeepInEditMode = True End If End Sub Sub DisplayValues(ByVal e As DetailsViewUpdatedEventArgs) MessageLabel.Text &= "<br/></br>" ' Iterate through the OldValue and NewValues ' properties and display the values. Dim i As Integer For i = 0 To e.OldValues.Count - 1 MessageLabel.Text &= "Old Value=" & e.OldValues(i).ToString() & _ ", New Value=" & e.NewValues(i).ToString() & "<br/>" Next MessageLabel.Text &= "</br>" End Sub </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> <title>DetailsViewUpdatedEventArgs Example</title> </head> <body> <form id="form1" runat="server"> <h3>DetailsViewUpdatedEventArgs Example</h3> <asp:detailsview id="CustomerDetailsView" datasourceid="DetailsViewSource" autogeneraterows="true" autogenerateeditbutton="true" allowpaging="true" datakeynames="CustomerID" onitemupdated="CustomerDetailsView_ItemUpdated" runat="server"> <pagersettings position="Bottom"/> </asp:detailsview> <br/> <asp:label id="MessageLabel" forecolor="Red" runat="server"/> <!-- 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" 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" connectionstring= "<%$ ConnectionStrings:NorthWindConnectionString%>" runat="server"/> </form> </body> </html>
Available since 2.0
