ObjectDataSource.DeleteMethod Właściwość

Definicja

Pobiera lub ustawia nazwę metody lub funkcji, która ObjectDataSource wywołuje formant w celu usunięcia danych.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

Wartość właściwości

String

Ciąg, który reprezentuje nazwę metody lub funkcji, której ObjectDataSource używa do usuwania danych.A string that represents the name of the method or function that the ObjectDataSource uses to delete data. Wartością domyślną jest ciąg pusty ("").The default is an empty string ("").

Przykłady

Ten rozdział zawiera dwa przykłady kodu.This section contains two code examples. Pierwszy przykład kodu demonstruje, jak używać ObjectDataSource obiektu z obiektem biznesowym i GridView kontrolki do usuwania danych.The first code example demonstrates how to use an ObjectDataSource object with a business object and a GridView control to delete data. Drugi przykład kodu przedstawia EmployeeLogic klasę, która jest używana w pierwszym przykładzie kodu.The second code example shows the EmployeeLogic class that is used in the first code example.

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. Początkowo GridView formant Wyświetla zestaw wszystkich pracowników przy użyciu metody, która jest określona przez SelectMethod Właściwość w celu pobrania danych z EmployeeLogic obiektu.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. 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.

Kliknięcie przycisku Usuń powoduje wykonanie operacji usuwania 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 operacji, i NorthwindEmployeeDeleted delegat jest wywoływany w celu obsłużenia Deleted zdarzenia po zakończeniu operacji w celu przeprowadzenia obsługi wyjątków.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. W tym przykładzie, jeśli NorthwindDataException jest zgłaszany, jest obsługiwany przez NorthwindDataException delegata.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>

Poniższy przykład kodu pokazuje EmployeeLogic klasę, która jest używana w poprzednim przykładzie kodu.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

Uwagi

Przy założeniu, że obiekt biznesowy usuwa dane po jednym rekordzie, a nie w partii.The business object is assumed to delete data one record at a time, rather than in a batch.

DeleteMethodWłaściwość delegowana do DeleteMethod właściwości ObjectDataSourceView obiektu, który jest skojarzony z ObjectDataSource formantem.The DeleteMethod property delegates to the DeleteMethod property of the ObjectDataSourceView object that is associated with the ObjectDataSource control.

Upewnij się, że nazwy parametrów skonfigurowane dla ObjectDataSource kontrolki w DeleteParameters kolekcji są zgodne z nazwami kolumn, które są zwracane przez metodę 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.

Okres istnienia obiektuObject Lifetime

Metodą identyfikowaną przez DeleteMethod Właściwość może być metoda wystąpienia lub static Shared metoda (w Visual Basic).The method that is identified by the DeleteMethod property can be an instance method or a static (Shared in Visual Basic) method. Jeśli jest to metoda wystąpienia, obiekt biznesowy jest tworzony i niszczony za każdym razem, gdy DeleteMethod Właściwość jest wywoływana.If it is an instance method, the business object is created and destroyed each time the DeleteMethod property is called. Można obsłużyć ObjectCreated zdarzenia i, ObjectCreating aby współdziałać z obiektem biznesowym przed DeleteMethod wywołaniem właściwości.You can handle the ObjectCreated and ObjectCreating events to work with the business object before the DeleteMethod property is called. Można także obsłużyć ObjectDisposing zdarzenie wywoływane po DeleteMethod wywołaniu właściwości.You can also handle the ObjectDisposing event that is raised after the DeleteMethod property is called. Jeśli obiekt biznesowy implementuje IDisposable interfejs, Dispose Metoda jest wywoływana przed zniszczeniem obiektu.If the business object implements the IDisposable interface, the Dispose method is called before the object is destroyed. Jeśli metoda jest static Shared metodą (w Visual Basic), obiekt biznesowy nigdy nie jest tworzony i nie można obsłużyć ObjectCreated ObjectCreating zdarzeń, i ObjectDisposing .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.

Scalanie parametrówParameter Merging

Parametry są dodawane do DeleteParameters kolekcji z trzech źródeł:Parameters are added to the DeleteParameters collection from three sources:

  • Z formantu powiązanego z danymi w czasie wykonywania.From the data-bound control, at run time.

  • Z DeleteParameters elementu deklaratywnie.From the DeleteParameters element, declaratively.

  • Z Deleting metody, deklaratywnie.From the Deleting method, declaratively.

Najpierw wszystkie parametry, które są generowane na podstawie formantów powiązanych z danymi, są dodawane do DeleteParameters kolekcji.First, any parameters that are generated from data-bound controls are added to the DeleteParameters collection. Na przykład, jeśli ObjectDataSource formant jest powiązany z GridView kontrolką, która ma kolumny Name i Number , parametry dla Name i Number są dodawane do kolekcji.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. Dokładna nazwa parametru zależy od OldValuesParameterFormatString właściwości.The exact name of the parameter depends on the OldValuesParameterFormatString property. Typem danych tych parametrów jest string .The data type of these parameters is string. Następnie parametry, które są wymienione w DeleteParameters elemencie są dodawane.Next, the parameters that are listed in the DeleteParameters element are added. Jeśli parametr w DeleteParameters elemencie zostanie znaleziony z taką samą nazwą jak parametr, który znajduje się już w DeleteParameters kolekcji, istniejący parametr zostanie zmodyfikowany w celu dopasowania do parametru, który jest określony w DeleteParameters elemencie.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. Zazwyczaj służy do modyfikowania typu danych w parametrze.Typically, this is used to modify the type of the data in the parameter. Na koniec można programowo dodawać i usuwać parametry w Deleting zdarzeniu, które są wykonywane przed Delete uruchomieniem metody.Finally, you can programmatically add and remove parameters in the Deleting event, which occurs before the Delete method is run. Metoda jest rozpoznawana po scaleniu parametrów.The method is resolved after the parameters are merged. Rozwiązanie metody zostało omówione w następnej sekcji.Method resolution is discussed in the next section.

Rozwiązanie metodyMethod Resolution

Gdy Delete Metoda jest wywoływana, pola danych z kontrolki powiązanej z danymi, parametry, które zostały utworzone w sposób deklaratywny w DeleteParameters elemencie i parametry, które zostały dodane w programie Deleting obsługi zdarzeń są scalone.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. (Aby uzyskać więcej informacji, zobacz poprzednią sekcję). ObjectDataSource Następnie obiekt podejmie próbę znalezienia metody do wywołania.(For more information, see the preceding section.) The ObjectDataSource object then attempts to find a method to call. Najpierw szuka jednej lub więcej metod o nazwie określonej we DeleteMethod właściwości.First, it looks for one or more methods with the name that is specified in the DeleteMethod property. Jeśli nie zostanie znalezione dopasowanie, InvalidOperationException zostanie zgłoszony wyjątek.If no match is found, an InvalidOperationException exception is thrown. W przypadku znalezienia dopasowania szuka pasujących nazw parametrów.If a match is found, it then looks for matching parameter names. Na przykład załóżmy, że typ, który jest określony przez TypeName Właściwość, ma dwie metody o nazwie DeleteARecord .For example, suppose the type that is specified by the TypeName property has two methods named DeleteARecord. Jeden DeleteARecord ma jeden parametr, ID , a drugi DeleteARecord ma dwa parametry, Name i Number .One DeleteARecord has one parameter, ID, and the other DeleteARecord has two parameters, Name and Number. Jeśli DeleteParameters Kolekcja ma tylko jeden parametr o nazwie ID , DeleteARecord wywoływana jest metoda z tylko ID parametrem.If the DeleteParameters collection has only one parameter named ID, the DeleteARecord method with just the ID parameter is called. Typ parametru nie jest sprawdzany w rozpoznawaniu metod.The type of the parameter is not checked in resolving the methods. Kolejność parametrów nie ma znaczenia.The order of the parameters does not matter.

Jeśli DataObjectTypeName Właściwość jest ustawiona, metoda jest rozpoznawana w inny sposób.If the DataObjectTypeName property is set, the method is resolved in a different way. ObjectDataSourceWyszukuje metodę o nazwie określonej we DeleteMethod właściwości, która przyjmuje jeden parametr typu, który jest określony we DataObjectTypeName właściwości.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. W takim przypadku nazwa parametru nie ma znaczenia.In this case, the name of the parameter does not matter.

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