FormView.ItemDeleting FormView.ItemDeleting FormView.ItemDeleting FormView.ItemDeleting Event

Definition

Tritt ein, wenn in einem FormView-Steuerelement auf eine Schaltfläche Löschen geklickt wird, allerdings bevor der Löschvorgang ausgeführt wird.Occurs when a Delete button within a FormView control is clicked, but before the delete operation.

public:
 event System::Web::UI::WebControls::FormViewDeleteEventHandler ^ ItemDeleting;
public event System.Web.UI.WebControls.FormViewDeleteEventHandler ItemDeleting;
member this.ItemDeleting : System.Web.UI.WebControls.FormViewDeleteEventHandler 
Public Custom Event ItemDeleting As FormViewDeleteEventHandler 

Beispiele

Im folgenden Beispiel wird veranschaulicht, wie das ItemDeleting -Ereignis verwendet wird, um einen Löschvorgang abzubrechen.The following example demonstrates how to use the ItemDeleting event to cancel a delete operation.


<%@ 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 EmployeeFormView_ItemDeleting(Object sender, FormViewDeleteEventArgs e)
  {
    // Get the employee ID, name, and job title from the Keys and Values
    // properties.
    String keyValue = e.Keys["EmployeeID"].ToString();
    String employeeName = e.Values["FirstName"].ToString() +
      " " + e.Values["LastName"].ToString();
    String title = 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"))
    {
      e.Cancel = true;
      MessageLabel.Text = "You cannot delete record " +
        e.RowIndex.ToString() + ". " + employeeName +
        " (Employee Number " + keyValue.ToString() +
        ") is protected.";
    }

  }
   
</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>


<%@ 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>

Hinweise

Das FormView -Steuerelement ItemDeleting löst das-Ereignis aus, FormView wenn auf eine Lösch CommandName Schaltfläche (eine Schaltfläche, deren-Eigenschaft auf "Delete" festgelegt ist) im-Steuerelement geklickt wirdThe 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. Dies ermöglicht es Ihnen, eine Ereignis Behandlungsmethode bereitzustellen, die eine benutzerdefinierte Routine ausführt, z. b. das Überprüfen eines Datensatzes vor dem Löschen, wenn dieses Ereignis auftritt.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.

Ein FormViewDeleteEventArgs -Objekt wird an die Ereignis Behandlungsmethode, mit der Sie den Index des zu löschenden Datensatzes ermitteln und angeben können, dass der Löschvorgang abgebrochen werden soll.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. Um den Index eines Datensatzes zu bestimmen, verwenden RowIndex Sie die-Eigenschaft.To determine the index of a record, use the RowIndex property. Um den Löschvorgang abzubrechen, legen Cancel Sie die true-Eigenschaft auf fest.To cancel the delete operation, set the Cancel property to true. Sie können auch die Schlüsselfelder und nichtschlüsselfelder zugreifen, mithilfe der Keys und Values Eigenschaften bzw.You can also access the key fields and non-key fields by using the Keys and Values properties, respectively.

Weitere Informationen zum Behandeln von Ereignissen finden Sie unter behandeln und Auslösen von Ereignissen.For more information about how to handle events, see Handling and Raising Events.

Gilt für:

Siehe auch