ObjectDataSourceView.OnDeleted(ObjectDataSourceStatusEventArgs) Metoda

Definicja

Podnosi Deleted zdarzenie po ObjectDataSourceView zakończeniu operacji usuwania przez obiekt.Raises the Deleted event after the ObjectDataSourceView object has completed a delete operation.

protected:
 virtual void OnDeleted(System::Web::UI::WebControls::ObjectDataSourceStatusEventArgs ^ e);
protected virtual void OnDeleted (System.Web.UI.WebControls.ObjectDataSourceStatusEventArgs e);
abstract member OnDeleted : System.Web.UI.WebControls.ObjectDataSourceStatusEventArgs -> unit
override this.OnDeleted : System.Web.UI.WebControls.ObjectDataSourceStatusEventArgs -> unit
Protected Overridable Sub OnDeleted (e As ObjectDataSourceStatusEventArgs)

Parametry

e
ObjectDataSourceStatusEventArgs

ObjectDataSourceStatusEventArgsZawierający dane zdarzenia.An ObjectDataSourceStatusEventArgs that contains the event data.

Przykłady

Poniższy przykład kodu ilustruje sposób używania ObjectDataSource kontrolki z obiektem biznesowym i GridView kontrolki do usuwania danych.The following code example demonstrates how to use an ObjectDataSource control with a business object and a GridView control to delete data. GridViewPoczątkowo wyświetla zestaw wszystkich pracowników przy użyciu metody, która jest określona przez SelectMethod Właściwość w celu pobrania danych z EmployeeLogic obiektu.The GridView initially displays a set of all employees, using the method that is specified by the SelectMethod property to retrieve the data from the EmployeeLogic object. Ponieważ AutoGenerateDeleteButton Właściwość jest ustawiona na true , GridView formant automatycznie wyświetla przycisk Usuń .Because the AutoGenerateDeleteButton property is set to true, the GridView control automatically displays a Delete button.

Jeśli klikniesz przycisk Usuń , Delete operacja zostanie wykonana przy użyciu metody, która jest określona przez DeleteMethod Właściwość i wszystkie parametry, które są określone w DeleteParameters kolekcji.If you click the Delete button, the Delete operation is performed using the method that is specified by the DeleteMethod property and any parameters that are specified in the DeleteParameters collection. W tym przykładzie kodu są również wykonywane niektóre kroki przetwarzania wstępnego i przetwarzania końcowego.In this code example, some preprocessing and post-processing steps are also performed. NorthwindEmployeeDeletingDelegat jest wywoływany, aby obsłużyć Deleting zdarzenie przed wykonaniem Delete operacji, i NorthwindEmployeeDeleted delegat jest wywoływany, aby obsłużyć Deleted zdarzenie po Delete zakończeniu operacji, aby wykonać obsługę wyjątków.The NorthwindEmployeeDeleting delegate is called to handle the Deleting event before the Delete operation is performed, and the NorthwindEmployeeDeleted delegate is called to handle the Deleted event after the Delete operation has completed, to perform an exception handling. W tym przykładzie, jeśli NorthwindDataException jest zgłaszany, jest obsługiwany przez tego delegata.In this example, if a NorthwindDataException is thrown, it is handled by this delegate.

Aby sprawdzić implementację EmployeeLogic obiektu biznesowego warstwy środkowej, który jest wykorzystywany przez ten przykład kodu, zobacz ObjectDataSourceStatusEventArgs .To examine the implementation of the EmployeeLogic middle-tier business object that this code example uses, see ObjectDataSourceStatusEventArgs.

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS" Assembly="Samples.AspNet.CS" %>
<%@ Import namespace="Samples.AspNet.CS" %>
<%@ 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">
private void NorthwindEmployeeDeleting(object source, ObjectDataSourceMethodEventArgs e)
{
  // The GridView passes the ID of the employee
  // to be deleted. However, the buisiness object, EmployeeLogic,
  // requires a NorthwindEmployee parameter, named "ne". Create
  // it now and add it to the parameters collection.
  IDictionary paramsFromPage = e.InputParameters;
  if (paramsFromPage["EmpID"] != null) {
    NorthwindEmployee ne
      = new NorthwindEmployee( Int32.Parse(paramsFromPage["EmpID"].ToString()));
    // Remove the old EmpID parameter.
    paramsFromPage.Clear();
    paramsFromPage.Add("ne", ne);
  }
}

private void NorthwindEmployeeDeleted(object source, ObjectDataSourceStatusEventArgs e)
{
  // Handle the Exception if it is a NorthwindDataException
  if (e.Exception != null)
  {

    // Handle the specific exception type. The ObjectDataSource wraps
    // any Exceptions in a TargetInvokationException wrapper, so
    // check the InnerException property for expected Exception types.
    if (e.Exception.InnerException is NorthwindDataException)
    {
      Label1.Text = e.Exception.InnerException.Message;
      // Because the exception is handled, there is
      // no reason to throw it.
      e.ExceptionHandled = true;
    }
  }
}

</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>ObjectDataSource - C# Example</title>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">

        <asp:gridview
          id="GridView1"
          runat="server"
          datasourceid="ObjectDataSource1"
          autogeneratedeletebutton="true"
          autogeneratecolumns="false"
          datakeynames="EmpID">
          <columns>
            <asp:boundfield headertext="EmpID" datafield="EmpID" />
            <asp:boundfield headertext="First Name" datafield="FirstName" />
            <asp:boundfield headertext="Last Name" datafield="LastName" />
          </columns>
        </asp:gridview>

        <asp:objectdatasource
          id="ObjectDataSource1"
          runat="server"
          selectmethod="GetAllEmployees"
          deletemethod="DeleteEmployee"
          ondeleting="NorthwindEmployeeDeleting"
          ondeleted="NorthwindEmployeeDeleted"
          typename="Samples.AspNet.CS.EmployeeLogic">
          <deleteparameters>
            <asp:parameter name="EmpID" type="Int32" />
          </deleteparameters>
        </asp:objectdatasource>

        <asp:label id="Label1" runat="server" />

    </form>
  </body>
</html>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB" Assembly="Samples.AspNet.VB" %>
<%@ Import namespace="Samples.AspNet.VB" %>
<%@ 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">
' Called before a Delete operation.
    Private Sub NorthwindEmployeeDeleting(ByVal source As Object, ByVal e As ObjectDataSourceMethodEventArgs)

        ' The GridView passes the ID of the employee
        ' to be deleted. However, the business object, EmployeeLogic,
        ' requires a NorthwindEmployee parameter, named "ne". Create
        ' it now and add it to the parameters collection.
        Dim paramsFromPage As IDictionary = e.InputParameters
  
        If Not paramsFromPage("EmpID") Is Nothing Then
    
            Dim ne As New NorthwindEmployee(paramsFromPage("EmpID").ToString())
            ' Remove the old EmpID parameter.
            paramsFromPage.Clear()
            paramsFromPage.Add("ne", ne)
    
    
        End If
    End Sub ' NorthwindEmployeeDeleting

    ' Called after a Delete operation.
    Private Sub NorthwindEmployeeDeleted(ByVal source As Object, ByVal e As ObjectDataSourceStatusEventArgs)
        ' Handle the Exception if it is a NorthwindDataException.
        If Not e.Exception Is Nothing Then

            ' Handle the specific exception type. The ObjectDataSource wraps
            ' any Exceptions in a TargetInvokationException wrapper, so
            ' check the InnerException property for the expected Exception types.
            If e.Exception.InnerException.GetType().Equals(GetType(NorthwindDataException)) Then

                Label1.Text = e.Exception.InnerException.Message
                ' Because the exception is handled, there is
                ' no reason to throw it.
                e.ExceptionHandled = True
      
            End If
        End If
    End Sub ' NorthwindEmployeeDeleted
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>ObjectDataSource - VB Example</title>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">

        <asp:gridview
          id="GridView1"
          runat="server"
          datasourceid="ObjectDataSource1"
          autogeneratedeletebutton="true"
          autogeneratecolumns="false"
          datakeynames="EmpID">
          <columns>
            <asp:boundfield headertext="EmpID" datafield="EmpID" />
            <asp:boundfield headertext="First Name" datafield="FirstName" />
            <asp:boundfield headertext="Last Name" datafield="LastName" />
          </columns>
        </asp:gridview>

        <asp:objectdatasource
          id="ObjectDataSource1"
          runat="server"
          selectmethod="GetAllEmployees"
          deletemethod="DeleteEmployee"
          ondeleting="NorthwindEmployeeDeleting"
          ondeleted="NorthwindEmployeeDeleted"
          typename="Samples.AspNet.VB.EmployeeLogic">
          <deleteparameters>
            <asp:parameter name="EmpID" type="Int32" />
          </deleteparameters>
        </asp:objectdatasource>

        <asp:label id="Label1" runat="server" />

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

Uwagi

Podnoszenie zdarzenia wywołuje program obsługi zdarzeń przez delegata.Raising an event invokes the event handler through a delegate. Aby uzyskać więcej informacji o sposobie obsługi zdarzeń, zobacz Obsługa iwywoływanie zdarzeń.For more information about how to handle events, see Handling and Raising Events.

OnDeletedMetoda umożliwia również klasom pochodnym obsłużenia zdarzenia bez dołączania delegata.The OnDeleted method also allows derived classes to handle the event without attaching a delegate. Jest to preferowana technika obsługi zdarzenia w klasie pochodnej.This is the preferred technique for handling the event in a derived class.

Uwagi dotyczące dziedziczenia

Podczas zastępowania OnDeleted(ObjectDataSourceStatusEventArgs) klasy pochodnej należy wywołać OnDeleted(ObjectDataSourceStatusEventArgs) metodę klasy bazowej, aby zarejestrowani delegowani odbierał zdarzenie.When overriding the OnDeleted(ObjectDataSourceStatusEventArgs) in a derived class, be sure to call the OnDeleted(ObjectDataSourceStatusEventArgs) method for the base class so that registered delegates receive the event.

Dotyczy

Zobacz też