DetailsViewDeleteEventHandler DetailsViewDeleteEventHandler DetailsViewDeleteEventHandler DetailsViewDeleteEventHandler Delegate

Definition

Stellt die Methode dar, die das ItemDeleting-Ereignis eines DetailsView-Steuerelements behandelt.Represents the method that handles the ItemDeleting event of a DetailsView control.

public delegate void DetailsViewDeleteEventHandler(System::Object ^ sender, DetailsViewDeleteEventArgs ^ e);
public delegate void DetailsViewDeleteEventHandler(object sender, DetailsViewDeleteEventArgs e);
type DetailsViewDeleteEventHandler = delegate of obj * DetailsViewDeleteEventArgs -> unit
Public Delegate Sub DetailsViewDeleteEventHandler(sender As Object, e As DetailsViewDeleteEventArgs)

Parameter

sender
Object Object Object Object

Die Quelle des Ereignisses.The source of the event.

Vererbung
DetailsViewDeleteEventHandlerDetailsViewDeleteEventHandlerDetailsViewDeleteEventHandlerDetailsViewDeleteEventHandler

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie ein DetailsViewDeleteEventHandler Delegat Programm DetailsView gesteuert dem ItemDeleting -Ereignis eines-Steuer Elements hinzugefügt wird.The following code example demonstrates how to programmatically add a DetailsViewDeleteEventHandler delegate to the ItemDeleting event of a DetailsView control.


<%@ 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 Page_Load(Object sender, EventArgs e)
  {
    
    // Create a new DetailsView object.
    DetailsView customerDetailsView = new DetailsView();
    
    // Set the DetailsView object's properties.
    customerDetailsView.ID = "CustomerDetailsView";
    customerDetailsView.DataSourceID = "DetailsViewSource";
    customerDetailsView.AutoGenerateRows = true;
    customerDetailsView.AutoGenerateDeleteButton = true;
    customerDetailsView.AllowPaging = true;
    customerDetailsView.PagerSettings.Mode = PagerButtons.NextPrevious;
    customerDetailsView.DataKeyNames = new String[1] { "CustomerID" };

    // Programmatically register the event-handling method
    // for the ItemDeleting event of a DetailsView control.
    customerDetailsView.ItemDeleting += new DetailsViewDeleteEventHandler(this.CustomerDetailsView_ItemDeleting);

    // Add the DetailsView object to the Controls collection
    // of the PlaceHolder control.
    DetailsViewPlaceHolder.Controls.Add(customerDetailsView);

  }

  void CustomerDetailsView_ItemDeleting(Object sender, DetailsViewDeleteEventArgs e)
  {

    // Get customer ID and name from the Keys and Values
    // properties.
    String keyValue = e.Keys["CustomerID"].ToString();
    String customerName = e.Values["CompanyName"].ToString();

    // Cancel the delete operation if the user attempts to 
    // delete protected record. In this example, records
    // with a customer ID that starts with with "A" cannot
    // be deleted.
    if (keyValue.StartsWith("A"))
    {
      e.Cancel = true;
      MessageLabel.Text = "You cannot delete " +
        customerName + ". This customer is protected.";
    }
    else
    {
      MessageLabel.Text = "Row " + e.RowIndex.ToString() +
        " deleted.";
    }

  }

</script>
 
 <html xmlns="http://www.w3.org/1999/xhtml" >   
  <head runat="server">
    <title>DetailsViewDeleteEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewDeleteEventHandler Example</h3>
        
        <!-- Use a PlaceHolder control as the container for the -->
        <!-- dynamically generated DetailsView control.         -->       
        <asp:PlaceHolder id="DetailsViewPlaceHolder"
          runat="server"/>
          
        <br/><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]"
          deletecommand="Delete [Customers] 
            Where [CustomerID]=@CustomerID"
          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 Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    
    ' Create a new DetailsView object.
    Dim customerDetailsView As New DetailsView()
    
    ' Set the DetailsView object's properties.
    customerDetailsView.ID = "CustomerDetailsView"
    customerDetailsView.DataSourceID = "DetailsViewSource"
    customerDetailsView.AutoGenerateRows = True
    customerDetailsView.AutoGenerateDeleteButton = True
    customerDetailsView.AllowPaging = True
    customerDetailsView.PagerSettings.Mode = PagerButtons.NextPrevious
    
    Dim keyArray() As String = {"CustomerID"}
    customerDetailsView.DataKeyNames = keyArray
    
    ' Programmatically register the event-handling method
    ' for the ItemDeleting event of a DetailsView control.
    AddHandler customerDetailsView.ItemDeleting, AddressOf CustomerDetailsView_ItemDeleting

    ' Add the DetailsView object to the Controls collection
    ' of the PlaceHolder control.
    DetailsViewPlaceHolder.Controls.Add(customerDetailsView)

  End Sub

  Sub CustomerDetailsView_ItemDeleting(ByVal sender As Object, ByVal e As DetailsViewDeleteEventArgs)

    ' Get customer ID and name from the Keys and Values
    ' properties.
    Dim keyValue As String = e.Keys("CustomerID").ToString()
    Dim customerName As String = e.Values("CompanyName").ToString()

    ' Cancel the delete operation if the user attempts to 
    ' delete protected record. In this example, records
    ' with a customer ID that starts with with "A" cannot
    ' be deleted.
    If keyValue.StartsWith("A") Then

      e.Cancel = True
      MessageLabel.Text = "You cannot delete " & _
        customerName & ". This customer is protected."
  
    Else
  
      MessageLabel.Text = "Row " & e.RowIndex.ToString() & _
        " deleted."
  
    End If
  
  End Sub

</script>
  
<html xmlns="http://www.w3.org/1999/xhtml" >    
  <head runat="server">
    <title>DetailsViewDeleteEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewDeleteEventHandler Example</h3>
        
        <!-- Use a PlaceHolder control as the container for the -->
        <!-- dynamically generated DetailsView control.         -->       
        <asp:PlaceHolder id="DetailsViewPlaceHolder"
          runat="server"/>
          
        <br/><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]"
          deletecommand="Delete [Customers] 
            Where [CustomerID]=@CustomerID"
          connectionstring=
            "<%$ ConnectionStrings:NorthWindConnectionString%>" 
          runat="server"/>
            
      </form>
  </body>
</html>

Im folgenden Codebeispiel wird veranschaulicht, wie ein DetailsViewDeleteEventHandler Delegat deklarativ dem ItemDeleting -Ereignis eines DetailsView -Steuer Elements hinzugefügt wird.The following code example demonstrates how to declaratively add a DetailsViewDeleteEventHandler delegate to the ItemDeleting event of a DetailsView control.


<%@ 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 CustomerDetailsView_ItemDeleting(Object sender, 
    DetailsViewDeleteEventArgs e)
  {

    // Get customer ID and name from the Keys and Values
    // properties.
    String keyValue = e.Keys["CustomerID"].ToString();
    String customerName = e.Values["CompanyName"].ToString();

    // Cancel the delete operation if the user attempts to 
    // delete protected record. In this example, records
    // with a customer ID that starts with with "A" cannot
    // be deleted.
    if (keyValue.StartsWith("A"))
    {
      e.Cancel = true;
      MessageLabel.Text = "You cannot delete " +
        customerName + ". This customer is protected.";
    }
    else
    {
      MessageLabel.Text = "Row " + e.RowIndex.ToString() +
        " deleted.";
    }

  }

</script>
 
 <html xmlns="http://www.w3.org/1999/xhtml" >   
  <head runat="server">
    <title>DetailsViewDeleteEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewDeleteEventHandler Example</h3>
        
        <asp:detailsview id="CustomerDetailsView"
          datasourceid="DetailsViewSource"
          autogeneraterows="true"
          autogeneratedeletebutton="true"
          allowpaging="true"
          datakeynames="CustomerID"
          onitemdeleting="CustomerDetailsView_ItemDeleting"  
          runat="server">
        
          <pagersettings mode="NextPrevious"/>
        
        </asp:detailsview>
          
        <br/><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]"
          deletecommand="Delete [Customers] 
            Where [CustomerID]=@CustomerID"
          connectionstring=
            "<%$ ConnectionStrings:NorthWindConnectionString%>" 
          runat="server"/>
            
      </form>
  </body>
</html>


<%@ page language="VB" autoeventwireup="false"%>
  
<!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_ItemDeleting(ByVal sender As Object, _
    ByVal e As DetailsViewDeleteEventArgs) _
    Handles CustomerDetailsView.ItemDeleting

    ' Get customer ID and name from the Keys and Values
    ' properties.
    Dim keyValue As String = e.Keys("CustomerID").ToString()
    Dim customerName As String = e.Values("CompanyName").ToString()

    ' Cancel the delete operation if the user attempts to 
    ' delete protected record. In this example, records
    ' with a customer ID that starts with with "A" cannot
    ' be deleted.
    If keyValue.StartsWith("A") Then

      e.Cancel = True
      MessageLabel.Text = "You cannot delete " & _
        customerName & ". This customer is protected."
  
    Else
  
      MessageLabel.Text = "Row " & e.RowIndex.ToString() & _
        " deleted."
  
    End If
  
  End Sub

</script>
  
<html xmlns="http://www.w3.org/1999/xhtml" >    
  <head runat="server">
    <title>DetailsViewDeleteEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewDeleteEventHandler Example</h3>
        
        <asp:detailsview id="CustomerDetailsView"
          datasourceid="DetailsViewSource"
          autogeneraterows="true"
          autogeneratedeletebutton="true"
          allowpaging="true"
          datakeynames="CustomerID" 
          runat="server">
        
          <pagersettings mode="NextPrevious"/>
        
        </asp:detailsview>
          
        <br/><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]"
          deletecommand="Delete [Customers] 
            Where [CustomerID]=@CustomerID"
          connectionstring=
            "<%$ ConnectionStrings:NorthWindConnectionString%>" 
          runat="server"/>
            
      </form>
  </body>
</html>

Hinweise

Das DetailsView -Steuerelement ItemDeleting löst das-Ereignis aus, DetailsView wenn auf eine Lösch CommandName Schaltfläche (eine Schaltfläche, deren-Eigenschaft auf "Delete" festgelegt ist) im-Steuerelement geklickt wirdThe DetailsView control raises the ItemDeleting event when a Delete button (a button with its CommandName property set to "Delete") within the control is clicked, but after the DetailsView control deletes the record. Dies ermöglicht Ihnen die Bereitstellung eines Ereignis Handlers, der eine benutzerdefinierte Routine ausführt, z. b. das Überprüfen der Ergebnisse eines Löschvorgangs, wenn dieses Ereignis auftritt.This allows you to provide an event handler that performs a custom routine, such as checking the results of a delete operation, whenever this event occurs.

Beim Erstellen eines DetailsViewDeleteEventHandler-Delegaten bestimmen Sie die Methode für die Ereignisbehandlung.When you create a DetailsViewDeleteEventHandler delegate, you identify the method that will handle the event. Um dem Ereignishandler das Ereignis zuzuordnen, fügen Sie dem Ereignis eine Instanz des Delegaten hinzu.To associate the event with your event handler, add an instance of the delegate to the event. Der Ereignishandler wird bei jedem Eintreten des Ereignisses aufgerufen, sofern der Delegat nicht entfernt wird.The event handler is called whenever the event occurs, unless you remove the delegate. Weitere Informationen zu Ereignishandlerdelegaten finden Sie unter behandeln und Auswerfen von Ereignissen.For more information about event-handler delegates, see Handling and Raising Events.

Erweiterungsmethoden

GetMethodInfo(Delegate) GetMethodInfo(Delegate) GetMethodInfo(Delegate) GetMethodInfo(Delegate)

Ruft ein Objekt ab, das die Methode darstellt, die vom angegebenen Delegaten dargestellt wird.Gets an object that represents the method represented by the specified delegate.

Gilt für:

Siehe auch