Export (0) Print
Expand All

FormView.ItemDeleting Event

Occurs when a Delete button within a FormView control is clicked, but before the delete operation.

Namespace:  System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)

'Declaration
Public Event ItemDeleting As FormViewDeleteEventHandler

The FormView control raises the ItemDeleting event when a Delete button (a button with its CommandName property set to "Delete") within the control is clicked, but before the FormView control deletes the record. This allows you to provide an event-handling method that performs a custom routine, such as verifying a record before deleting it, whenever this event occurs.

A FormViewDeleteEventArgs object is passed to the event-handling method, which allows you to determine the index of the record being deleted and to indicate that the delete operation should be canceled. To determine the index of a record, use the RowIndex property. To cancel the delete operation, set the Cancel property to true. You can also access the key fields and non-key fields by using the Keys and Values properties, respectively.

For more information about handling events, see Consuming Events.

The following example demonstrates how to use the ItemDeleting event to cancel a delete operation.


<%@ 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 EmployeeFormView_ItemDeleting(ByVal sender As Object, ByVal e As FormViewDeleteEventArgs)

    ' Get the employee ID, name, and job title from the Keys and Values
    ' properties.
    Dim keyValue As String = e.Keys("EmployeeID").ToString()
    Dim employeeName As String = e.Values("FirstName").ToString() & _
      " " & e.Values("LastName").ToString()
    Dim title As String = e.Values("Title").ToString()

    ' Cancel the delete operation if the user attempts to 
    ' delete a protected record. In this example, records for
    ' employees with a "Sales Manager" job title are protected.
    If Title.Equals("Sales Manager") Then

      e.Cancel = True
      MessageLabel.Text = "You cannot delete record " & _
        e.RowIndex.ToString() & ". " & employeeName & _
        " (Employee Number " & keyValue.ToString() & _
        ") is protected."

    End If

  End Sub

</script>

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

      <h3>FormViewDeleteEventArgs Example</h3>

      <asp:formview id="EmployeeFormView"
        datasourceid="EmployeeSource"
        allowpaging="true"
        datakeynames="EmployeeID"
        onitemdeleting="EmployeeFormView_ItemDeleting"  
        runat="server">

        <itemtemplate>

          <table>
            <tr>
              <td>
                <asp:image id="EmployeeImage"
                  imageurl='<%# Eval("PhotoPath") %>'
                  alternatetext='<%# Eval("LastName") %>' 
                  runat="server"/>
              </td>
              <td>
                <asp:label id="FirstNameLabel"
                  text='<%#Bind("FirstName")%>'
                  font-bold="true"
                  runat="server"/>
                <asp:label id="LastNameLabel"
                  text='<%#Bind("LastName")%>'
                  font-bold="true"
                  runat="server"/>
                <br/>     
                <asp:label id="TitleLabel"
                  text='<%#Bind("Title")%>'
                  runat="server"/>        
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:button id="DeleteButton"
                  text="Delete Record"
                  commandname="Delete"
                  runat="server" />
              </td>
            </tr>
          </table>

        </itemtemplate>         

      </asp:formview>

      <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="EmployeeSource"
        selectcommand="Select [EmployeeID], [LastName], [FirstName], [Title], [PhotoPath] From [Employees]"
        deletecommand="Delete [Employees] Where [EmployeeID]=@EmployeeID"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>

    </form>
  </body>
</html>

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0
Show:
© 2015 Microsoft