ObjectDataSource.DeleteMethod Proprietà

Definizione

Ottiene o imposta il nome del metodo o funzione che il controllo ObjectDataSource richiama per eliminare dati.Gets or sets the name of the method or function that the ObjectDataSource control invokes to delete data.

public:
 property System::String ^ DeleteMethod { System::String ^ get(); void set(System::String ^ value); };
public string DeleteMethod { get; set; }
member this.DeleteMethod : string with get, set
Public Property DeleteMethod As String

Valore della proprietà

Stringa che rappresenta il nome del metodo o funzione che l'oggetto ObjectDataSource utilizza per eliminare i dati.A string that represents the name of the method or function that the ObjectDataSource uses to delete data. Il valore predefinito è una stringa vuota ("").The default is an empty string ("").

Esempi

In questa sezione sono riportati due esempi di codice.This section contains two code examples. Nel primo esempio di codice viene illustrato come utilizzare ObjectDataSource un oggetto con un oggetto business e GridView un controllo per eliminare i dati.The first code example demonstrates how to use an ObjectDataSource object with a business object and a GridView control to delete data. Nel secondo esempio di codice viene EmployeeLogic illustrata la classe utilizzata nel primo esempio di codice.The second code example shows the EmployeeLogic class that is used in the first code example.

Nell'esempio di codice riportato di seguito viene illustrato ObjectDataSource come utilizzare un controllo con un oggetto GridView business e un controllo per eliminare i dati.The following code example demonstrates how to use an ObjectDataSource control with a business object and a GridView control to delete data. Inizialmente, il GridView controllo Visualizza un set di tutti i dipendenti, usando il metodo specificato SelectMethod dalla proprietà per EmployeeLogic recuperare i dati dall'oggetto.Initially, the GridView control displays a set of all employees, using the method that is specified by the SelectMethod property to retrieve the data from the EmployeeLogic object. Poiché la AutoGenerateDeleteButton proprietà è impostata su true, il GridView controllo Visualizza automaticamente un pulsante Elimina .Because the AutoGenerateDeleteButton property is set to true, the GridView control automatically displays a Delete button.

Se si fa clic sul pulsante Elimina , l'operazione di eliminazione viene eseguita utilizzando il metodo specificato dalla DeleteMethod proprietà e tutti i parametri specificati nella DeleteParameters raccolta.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. In questo esempio di codice vengono eseguiti anche alcuni passaggi di pre-elaborazione e post-elaborazione.In this code example, some preprocessing and post-processing steps are also performed. Il NorthwindEmployeeDeleting delegato viene chiamato per gestire l' Deleting evento prima dell'esecuzione dell'operazione e il NorthwindEmployeeDeleted delegato viene chiamato per gestire l' Deleted evento dopo il completamento dell'operazione per eseguire la gestione delle eccezioni.The NorthwindEmployeeDeleting delegate is called to handle the Deleting event before the operation is performed, and the NorthwindEmployeeDeleted delegate is called to handle the Deleted event after the operation has completed to perform exception handling. In questo esempio, se viene NorthwindDataException generata un'eccezione, questa viene gestita NorthwindDataException dal delegato.In this example, if a NorthwindDataException is thrown, it is handled by the NorthwindDataException delegate.

<%@ 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>

Nell'esempio di codice riportato di EmployeeLogic seguito viene illustrata la classe utilizzata nell'esempio di codice precedente.The following code example shows the EmployeeLogic class that is used in the preceding code example.

namespace Samples.AspNet.CS {

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Web.UI;
using System.Web.UI.WebControls;
  //
  // EmployeeLogic is a stateless business object that encapsulates
  // the operations you can perform on a NorthwindEmployee object.
  //
  public class EmployeeLogic {

    // Returns a collection of NorthwindEmployee objects.
    public static ICollection GetAllEmployees () {
      ArrayList al = new ArrayList();

      // Use the SqlDataSource class to wrap the
      // ADO.NET code required to query the database.
      ConnectionStringSettings cts = ConfigurationManager.ConnectionStrings["NorthwindConnection"];

      SqlDataSource sds
        = new SqlDataSource(cts.ConnectionString,
                            "SELECT EmployeeID FROM Employees");
      try {
        IEnumerable IDs = sds.Select(DataSourceSelectArguments.Empty);

        // Iterate through the Enumeration and create a
        // NorthwindEmployee object for each ID.
        IEnumerator enumerator = IDs.GetEnumerator();
        while (enumerator.MoveNext()) {
          // The IEnumerable contains DataRowView objects.
          DataRowView row = enumerator.Current as DataRowView;
          string id = row["EmployeeID"].ToString();
          NorthwindEmployee nwe = new NorthwindEmployee(id);
          // Add the NorthwindEmployee object to the collection.
          al.Add(nwe);
        }
      }
      finally {
        // If anything strange happens, clean up.
        sds.Dispose();
      }

      return al;
    }

    public static NorthwindEmployee GetEmployee(object anID) {
      return new NorthwindEmployee(anID);
    }

    public static void DeleteEmployee(NorthwindEmployee ne) {
      bool retval = ne.Delete();
      if (! retval) { throw new NorthwindDataException("Employee delete failed."); }
      // Delete the object in memory.
      ne = null;
    }

    public static void DeleteEmployeeByID(int anID) {
        NorthwindEmployee tempEmp = new NorthwindEmployee(anID);
        DeleteEmployee(tempEmp);
    }
  }

  public class NorthwindEmployee {

    public NorthwindEmployee () {
      ID = DBNull.Value;
      lastName = "";
      firstName = "";
    }

    public NorthwindEmployee (object anID) {
      this.ID = anID;

      ConnectionStringSettings cts = ConfigurationManager.ConnectionStrings["NorthwindConnection"];

      SqlConnection conn = new SqlConnection (cts.ConnectionString);
      SqlCommand sc =
        new SqlCommand(" SELECT FirstName,LastName " +
                       " FROM Employees " +
                       " WHERE EmployeeID = @empId",
                       conn);
      // Add the employee ID parameter and set its value.
      sc.Parameters.Add(new SqlParameter("@empId",SqlDbType.Int)).Value = Int32.Parse(anID.ToString());
      SqlDataReader sdr = null;

      try {
        conn.Open();
        sdr = sc.ExecuteReader();

        // This is not a while loop. It only loops once.
        if (sdr != null && sdr.Read()) {
          // The IEnumerable contains DataRowView objects.
          this.firstName        = sdr["FirstName"].ToString();
          this.lastName         = sdr["LastName"].ToString();
        }
        else {
          throw new NorthwindDataException("Data not loaded for employee id.");
        }
      }
      finally {
        try {
          if (sdr != null) sdr.Close();
          conn.Close();
        }
        catch (SqlException) {
          // Log an event in the Application Event Log.
          throw;
        }
      }
    }

    private object ID;
    public object EmpID {
      get { return ID; }
    }

    private string lastName;
    public string LastName {
      get { return lastName; }
      set { lastName = value; }
    }

    private string firstName;
    public string FirstName {
      get { return firstName; }
      set { firstName = value;  }
    }
    public bool Delete () {
      if (ID.Equals(DBNull.Value)) {
        // The Employee object is not persisted.
        return true;
      }
      else {
        // The Employee object is persisted.
        // Use the SqlDataSource control as a convenient wrapper for
        // the ADO.NET code needed to delete a record from the database.
        ConnectionStringSettings cts = ConfigurationManager.ConnectionStrings["NorthwindConnection"];
        SqlDataSource sds = new SqlDataSource();

        try {
          sds.ConnectionString = cts.ConnectionString;
          sds.DeleteParameters.Add(new Parameter("empID", TypeCode.Int32, this.ID.ToString()));
          sds.DeleteCommand = "DELETE FROM [Order Details] " + 
              "WHERE OrderID IN (SELECT OrderID FROM Orders WHERE EmployeeID=@empID)";
          sds.Delete();
          sds.DeleteCommand = "DELETE FROM Orders WHERE EmployeeID=@empID";
          sds.Delete();
          sds.DeleteCommand = "DELETE FROM EmployeeTerritories WHERE EmployeeID=@empID";
          sds.Delete();
          sds.DeleteCommand = "DELETE FROM Employees WHERE EmployeeID=@empID";
          sds.Delete();
          return true;
        }
        finally {
          // Clean up resources.
          sds.Dispose();
        }
      }
    }
  }

  public class NorthwindDataException: Exception {
    public NorthwindDataException(string msg) : base (msg) { }
  }
}
Imports System.Collections
Imports System.Configuration
Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.UI
Imports System.Web.UI.WebControls

Namespace Samples.AspNet.VB
'
' EmployeeLogic is a stateless business object that encapsulates
' the operations you can perform on a NorthwindEmployee object.
Public Class EmployeeLogic

   ' Return a collection of NorthwindEmployee objects.
   Public Shared Function GetAllEmployees() As ICollection
      Dim al As New ArrayList()

      ' Use the SqlDataSource class to wrap the
      ' ADO.NET code required to query the database.
      Dim cts As ConnectionStringSettings = ConfigurationManager.ConnectionStrings("NorthwindConnection")
      Dim sds As New SqlDataSource(cts.ConnectionString, _
                                  "SELECT EmployeeID FROM Employees")
      Try
         Dim IDs As IEnumerable = sds.Select(DataSourceSelectArguments.Empty)

         ' Iterate through the Enumeration and create a
         ' NorthwindEmployee object for each ID.
         Dim enumerator As IEnumerator = IDs.GetEnumerator()
         While enumerator.MoveNext()
            ' The IEnumerable contains DataRowView objects.
            Dim row As DataRowView = CType(enumerator.Current,DataRowView)
            Dim id As String = row("EmployeeID").ToString()
            Dim nwe As New NorthwindEmployee(id)
            ' Add the NorthwindEmployee object to the collection.
            al.Add(nwe)
         End While
      Finally
         ' If anything strange happens, clean up.
         sds.Dispose()
      End Try

      Return al
   End Function 'GetAllEmployees


   Public Shared Function GetEmployee(anID As Object) As NorthwindEmployee
      Return New NorthwindEmployee(anID)
   End Function 'GetEmployee


   Public Shared Sub DeleteEmployee(ne As NorthwindEmployee)
      Dim retval As Boolean = ne.Delete()
      If Not retval Then
         Throw New NorthwindDataException("Employee delete failed.")
      End If ' Delete the object in memory.
      ne = Nothing
   End Sub


   Public Shared Sub DeleteEmployeeByID(anID As Integer)
      Dim tempEmp As New NorthwindEmployee(anID)
      DeleteEmployee(tempEmp)
   End Sub

End Class

Public Class NorthwindEmployee

   Public Sub New()
      ID = DBNull.Value
      aLastName = ""
      aFirstName = ""
   End Sub


   Public Sub New(anID As Object)
      Me.ID = anID
      Dim cts As ConnectionStringSettings = ConfigurationManager.ConnectionStrings("NorthwindConnection")
      Dim conn As New SqlConnection(cts.ConnectionString)
      Dim sc As New SqlCommand(" SELECT FirstName,LastName " & _
                               " FROM Employees " & _
                               " WHERE EmployeeID = @empId", conn)
      ' Add the employee ID parameter and set its value.
      sc.Parameters.Add(New SqlParameter("@empId", SqlDbType.Int)).Value = Int32.Parse(anID.ToString())
      Dim sdr As SqlDataReader = Nothing

      Try
         conn.Open()
         sdr = sc.ExecuteReader()

         ' This is not a while loop. It only loops once.
         If Not (sdr Is Nothing) AndAlso sdr.Read() Then
            ' The IEnumerable contains DataRowView objects.
            Me.aFirstName = sdr("FirstName").ToString()
            Me.aLastName = sdr("LastName").ToString()
         Else
            Throw New NorthwindDataException("Data not loaded for employee id.")
         End If
      Finally
         Try
            If Not (sdr Is Nothing) Then
               sdr.Close()
            End If
            conn.Close()
         Catch se As SqlException
            ' Log an event in the Application Event Log.
            Throw
         End Try
      End Try
   End Sub

   Private ID As Object
   Public ReadOnly Property EmpID() As Object
      Get
         Return ID
      End Get
   End Property

   Private aLastName As String
   Public Property LastName() As String
      Get
         Return aLastName
      End Get
      Set
         aLastName = value
      End Set
   End Property

   Private aFirstName As String
   Public Property FirstName() As String
      Get
         Return aFirstName
      End Get
      Set
         aFirstName = value
      End Set
   End Property

   Public Function Delete() As Boolean
      If ID.Equals(DBNull.Value) Then
         ' The Employee object is not persisted.
         Return True
      Else
         ' The Employee object is persisted.
         ' Use the SqlDataSource control as a convenient wrapper for
         ' the ADO.NET code needed to delete a record from the database.
         Dim cts As ConnectionStringSettings = ConfigurationManager.ConnectionStrings("NorthwindConnection")
         Dim sds As New SqlDataSource()
         Try
            sds.ConnectionString = cts.ConnectionString
            sds.DeleteParameters.Add(New Parameter("empID", TypeCode.Int32, Me.ID.ToString()))
            sds.DeleteCommand = "DELETE FROM [Order Details] " & _
                "WHERE OrderID IN (SELECT OrderID FROM Orders WHERE EmployeeID=@empID)"
            sds.Delete()
            sds.DeleteCommand = "DELETE FROM Orders WHERE EmployeeID=@empID"
            sds.Delete()
            sds.DeleteCommand = "DELETE FROM EmployeeTerritories WHERE EmployeeID=@empID"
            sds.Delete()
            sds.DeleteCommand = "DELETE FROM Employees WHERE EmployeeID=@empID"
            sds.Delete()
            Return True
         Finally
            ' Clean up resources.
            sds.Dispose()
         End Try
      End If
   End Function 'Delete
End Class

Public Class NorthwindDataException
   Inherits Exception

   Public Sub New(msg As String)
      MyBase.New(msg)
   End Sub

End Class
End Namespace

Commenti

Si presuppone che l'oggetto business elimini i dati un record alla volta, anziché in un batch.The business object is assumed to delete data one record at a time, rather than in a batch.

La DeleteMethod proprietà delega DeleteMethod alla proprietà dell' ObjectDataSourceView oggetto associato ObjectDataSource al controllo.The DeleteMethod property delegates to the DeleteMethod property of the ObjectDataSourceView object that is associated with the ObjectDataSource control.

Verificare che i nomi dei parametri configurati ObjectDataSource per il controllo DeleteParameters nella raccolta corrispondano ai nomi di colonna restituiti dal metodo Select.Make sure that the parameter names configured for the ObjectDataSource control in the DeleteParameters collection match the column names that are returned by the select method.

Durata dell'oggettoObject Lifetime

Il metodo identificato dalla DeleteMethod proprietà può essere un metodo di istanza o un static metodo (Shared in Visual Basic).The method that is identified by the DeleteMethod property can be an instance method or a static (Shared in Visual Basic) method. Se si tratta di un metodo di istanza, l'oggetto business viene creato ed eliminato ogni DeleteMethod volta che viene chiamata la proprietà.If it is an instance method, the business object is created and destroyed each time the DeleteMethod property is called. È possibile gestire ObjectCreated gli eventi ObjectCreating e per utilizzare l'oggetto business prima della chiamata DeleteMethod della proprietà.You can handle the ObjectCreated and ObjectCreating events to work with the business object before the DeleteMethod property is called. È anche possibile gestire l' ObjectDisposing evento generato dopo la chiamata della DeleteMethod proprietà.You can also handle the ObjectDisposing event that is raised after the DeleteMethod property is called. Se l'oggetto business implementa l' IDisposable interfaccia, il Dispose metodo viene chiamato prima che l'oggetto venga eliminato definitivamente.If the business object implements the IDisposable interface, the Dispose method is called before the object is destroyed. Se il metodo è un static metodoShared (in Visual Basic), l'oggetto business non viene mai creato e non è possibile ObjectCreatedgestire ObjectCreatinggli eventi ObjectDisposing , e.If the method is a static (Shared in Visual Basic) method, the business object is never created and you cannot handle the ObjectCreated, ObjectCreating, and ObjectDisposing events.

Unione di parametriParameter Merging

I DeleteParameters parametri vengono aggiunti alla raccolta da tre origini:Parameters are added to the DeleteParameters collection from three sources:

  • Dal controllo associato a dati, in fase di esecuzione.From the data-bound control, at run time.

  • DeleteParameters Dall'elemento, in modo dichiarativo.From the DeleteParameters element, declaratively.

  • Deleting Dal metodo, in modo dichiarativo.From the Deleting method, declaratively.

In primo luogo, tutti i parametri generati dai controlli associati a dati vengono aggiunti alla DeleteParameters raccolta.First, any parameters that are generated from data-bound controls are added to the DeleteParameters collection. Ad esempio, se il ObjectDataSource controllo è associato a un GridView controllo con le colonne Name e Number, i parametri per Name e Number vengono aggiunti alla raccolta.For example, if the ObjectDataSource control is bound to a GridView control that has the columns Name and Number, parameters for Name and Number are added to the collection. Il nome esatto del parametro dipende OldValuesParameterFormatString dalla proprietà.The exact name of the parameter depends on the OldValuesParameterFormatString property. Il tipo di dati di questi parametri stringè.The data type of these parameters is string. Vengono quindi aggiunti i parametri elencati nell' DeleteParameters elemento.Next, the parameters that are listed in the DeleteParameters element are added. Se un parametro nell' DeleteParameters elemento viene trovato con lo stesso nome di un parametro già presente DeleteParameters nella raccolta, il parametro esistente viene modificato in modo che corrisponda al parametro specificato nell' DeleteParameters elemento.If a parameter in the DeleteParameters element is found with the same name as a parameter that is already in the DeleteParameters collection, the existing parameter is modified to match the parameter that is specified in the DeleteParameters element. Viene in genere utilizzato per modificare il tipo di dati nel parametro.Typically, this is used to modify the type of the data in the parameter. Infine, è possibile aggiungere e rimuovere i parametri nell' Deleting evento a livello di codice, che si verifica prima dell'esecuzione del Delete metodo.Finally, you can programmatically add and remove parameters in the Deleting event, which occurs before the Delete method is run. Il metodo viene risolto dopo l'Unione dei parametri.The method is resolved after the parameters are merged. La risoluzione dei metodi viene descritta nella sezione successiva.Method resolution is discussed in the next section.

Risoluzione del metodoMethod Resolution

Quando viene Delete chiamato il metodo, i campi dati del controllo associato DeleteParameters a dati, i parametri creati in modo dichiarativo nell'elemento e i parametri aggiunti nel Deleting gestore eventi vengono uniti.When the Delete method is called, the data fields from the data-bound control, the parameters that were created declaratively in the DeleteParameters element, and the parameters that were added in the Deleting event handler are all merged. Per ulteriori informazioni, vedere la sezione precedente. L' ObjectDataSource oggetto tenta quindi di trovare un metodo da chiamare.(For more information, see the preceding section.) The ObjectDataSource object then attempts to find a method to call. Innanzitutto, cerca uno o più metodi con il nome specificato nella DeleteMethod proprietà.First, it looks for one or more methods with the name that is specified in the DeleteMethod property. Se non viene trovata alcuna corrispondenza, InvalidOperationException viene generata un'eccezione.If no match is found, an InvalidOperationException exception is thrown. Se viene trovata una corrispondenza, Cerca i nomi dei parametri corrispondenti.If a match is found, it then looks for matching parameter names. Si supponga, ad esempio, che il tipo specificato dalla TypeName proprietà disponga di due metodi DeleteARecorddenominati.For example, suppose the type that is specified by the TypeName property has two methods named DeleteARecord. Uno DeleteARecord ha un parametro, ID, e l'altro DeleteARecord ha due parametri, Name e Number.One DeleteARecord has one parameter, ID, and the other DeleteARecord has two parameters, Name and Number. Se la DeleteParameters raccolta ha un solo parametro denominato ID, viene DeleteARecord chiamato il metodo con ID solo il parametro.If the DeleteParameters collection has only one parameter named ID, the DeleteARecord method with just the ID parameter is called. Il tipo del parametro non è archiviato per la risoluzione dei metodi.The type of the parameter is not checked in resolving the methods. L'ordine dei parametri non è rilevante.The order of the parameters does not matter.

Se la DataObjectTypeName proprietà è impostata, il metodo viene risolto in modo diverso.If the DataObjectTypeName property is set, the method is resolved in a different way. Il ObjectDataSource Cerca un metodo con il nome specificato DeleteMethod nella proprietà che accetta un parametro del tipo specificato nella DataObjectTypeName proprietà.The ObjectDataSource looks for a method with the name that is specified in the DeleteMethod property that takes one parameter of the type that is specified in the DataObjectTypeName property. In questo caso, il nome del parametro non è rilevante.In this case, the name of the parameter does not matter.

Si applica a

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