DetailsViewUpdateEventArgs Class
Provides data for the ItemUpdating event.
Assembly: System.Web (in System.Web.dll)
System.EventArgs
System.ComponentModel.CancelEventArgs
System.Web.UI.WebControls.DetailsViewUpdateEventArgs
| Name | Description | |
|---|---|---|
![]() | DetailsViewUpdateEventArgs(Object) | Initializes a new instance of the DetailsViewUpdateEventArgs class. |
| Name | Description | |
|---|---|---|
![]() | Cancel | Gets or sets a value indicating whether the event should be canceled.(Inherited from CancelEventArgs.) |
![]() | CommandArgument | Gets the command argument for the update operation passed to the DetailsView control. |
![]() | Keys | Gets a dictionary that contains the key field name/value pairs for the record to update. |
![]() | NewValues | Gets a dictionary that contains the new field name/value pairs for the record to update. |
![]() | OldValues | Gets a dictionary that contains the original field name/value pairs for the record to update. |
| Name | Description | |
|---|---|---|
![]() | Equals(Object) | Determines whether the specified object is equal to the current object.(Inherited from Object.) |
![]() | Finalize() | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.) |
![]() | GetHashCode() | Serves as the default hash function. (Inherited from Object.) |
![]() | GetType() | |
![]() | MemberwiseClone() | |
![]() | ToString() | Returns a string that represents the current object.(Inherited from Object.) |
The DetailsView control raises the ItemUpdating event when an Update button (a button with its CommandName property set to "Update") within the control is clicked, but before the DetailsView control updates the record. This allows you to provide an event handler that performs a custom routine, such as HTML-encoding the values of a record before updating it in the data source, whenever this event occurs.
A DetailsViewUpdateEventArgs object is passed to the event handler, which allows you to determine the value of an optional command argument sent to the DetailsView control and to indicate whether the update operation should be canceled. To determine the value of the command argument, use the CommandArgument property. To cancel the update operation, set the Cancel property to true. You can also read or modify the new values entered by the user by using the Keys and NewValues properties. The Keys property contains the key fields, while the NewValues property contains the non-key fields. If you need to access the original non-key field values, use the OldValues property.
For more information about handling events, see NIB: Consuming Events.
For a list of initial property values for an instance of the DetailsViewUpdateEventArgs class, see the DetailsViewUpdateEventArgs constructor.
The following code example demonstrates how to use the DetailsViewUpdateEventArgs object passed to the event handler for the ItemUpdating event to validate the values entered by the user.
<%@ 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_ItemUpdating(ByVal sender As Object, _ ByVal e As DetailsViewUpdateEventArgs) ' Validate the field values entered by the user. This ' example determines whether the user left any fields ' empty. Use the NewValues property to access the new ' values entered by the user. Dim emptyFieldList As ArrayList = _ ValidateFields(CType(e.NewValues, IOrderedDictionary)) If emptyFieldList.Count > 0 Then ' The user left some fields empty. Display an error message. ' Use the Keys property to retrieve the key field value. Dim keyValue As String = e.Keys("CustomerID").ToString() MessageLabel.Text = _ "You must enter a value for all fields of record " & _ keyValue & ".<br/>The following fields are missing:<br/><br/>" ' Display the missing fields. Dim value As String For Each value In emptyFieldList ' Use the OldValues property access the original value ' of a field. MessageLabel.Text &= value & " - Original Value = " & _ e.OldValues(value).ToString() & "<br />" Next ' Cancel the update operation. e.Cancel = True Else ' The field values passed validation. Clear the ' error message label. MessageLabel.Text = "" End If End Sub Function ValidateFields(ByVal list As IOrderedDictionary) _ As ArrayList ' Create an ArrayList object to store the ' names of any empty fields. Dim emptyFieldList As New ArrayList() ' Iterate though the field values entered by ' the user and check for an empty field. Empty ' fields contain a null value. Dim entry As DictionaryEntry For Each entry In list If entry.Value Is Nothing Then ' Add the field name to the ArrayList object. emptyFieldList.Add(entry.Key.ToString()) End If Next Return emptyFieldList End Function Sub CustomerDetailsView_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs) If e.CancelingEdit Then ' The user canceled the update operation. ' Clear the error message label. MessageLabel.Text = "" End If End Sub </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> <title>DetailsViewUpdateEventArgs Example</title> </head> <body> <form id="form1" runat="server"> <h3>DetailsViewUpdateEventArgs Example</h3> <asp:detailsview id="CustomerDetailsView" datasourceid="DetailsViewSource" autogeneraterows="true" autogenerateeditbutton="true" allowpaging="true" datakeynames="CustomerID" onitemupdating="CustomerDetailsView_ItemUpdating" onmodechanging="CustomerDetailsView_ModeChanging" 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
Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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