ObjectDataSourceMethodEventArgs Class

Note: This class is new in the .NET Framework version 2.0.

Provides data for the Inserting, Updating, and Deleting events of the ObjectDataSource control.

Namespace: System.Web.UI.WebControls
Assembly: System.Web (in system.web.dll)

'Declaration
Public Class ObjectDataSourceMethodEventArgs
	Inherits CancelEventArgs
'Usage
Dim instance As ObjectDataSourceMethodEventArgs

public class ObjectDataSourceMethodEventArgs extends CancelEventArgs
public class ObjectDataSourceMethodEventArgs extends CancelEventArgs

The ObjectDataSourceMethodEventArgs class is used in the OnSelecting, OnUpdating, OnInserting, and OnDeleting methods to provide access to input parameters that are passed to the Select, Update, Delete, and Insert methods of the ObjectDataSource control. These parameters are accessed using the InputParameters property. By adding a delegate to handle the Selecting, Updating, Inserting, or Deleting event, you can examine and manipulate the values of the parameters and perform any additional preprocessing that is required. Any changes to the parameters in this dictionary will affect which method overload is called for the operation. When the DataObjectTypeName property of the ObjectDataSource control is set, you can only modify the data object properties for the items in this dictionary; you cannot add or remove parameters. For more information, see Delete.

The ObjectDataSource control exposes many events that you can handle to work with the underlying business object at various times in its life cycle. The following table lists the events and associated EventArgs classes and event handler delegates.

Event

EventArgs class

EventHandler delegate

ObjectCreating.

Occurs immediately before the instance of the business object is created.

ObjectDataSourceEventArgs

ObjectDataSourceObjectEventHandler

ObjectCreated.

Occurs immediately after the instance of the business object is created.

ObjectDataSourceEventArgs

ObjectDataSourceObjectEventHandler

Selecting.

Occurs before the data is retrieved.

ObjectDataSourceSelectingEventArgs

ObjectDataSourceSelectingEventHandler

Inserting, Updating, and Deleting.

Occur before an insert, update, or delete operation is performed.

ObjectDataSourceMethodEventArgs

ObjectDataSourceMethodEventHandler

Selected.

Occurs after the data is retrieved.

ObjectDataSourceStatusEventArgs

ObjectDataSourceStatusEventHandler

Inserted, Updated, and Deleted.

Occur after the insert, update, or delete operation is completed.

ObjectDataSourceStatusEventArgs

ObjectDataSourceStatusEventHandler

ObjectDisposing.

Occurs before a business object is destroyed.

ObjectDataSourceDisposingEventArgs

ObjectDataSourceDisposingEventHandler

This section contains two code examples. The first code example demonstrates how to use an ObjectDataSource control with a business object and a DetailsView control to insert data. The second code example provides an example middle-tier business object that is used by the first code example.

The following code example demonstrates how to use an ObjectDataSource control with a business object and a DetailsView control to insert data. The DetailsView initially displays a new NorthwindEmployee record, along with an automatically generated Insert button. After you enter data into the fields of the DetailsView control, click the Insert button, and the InsertMethod property will identify which method performs the Insert action.

In this example, the UpdateEmployeeInfo method is used to perform an insert; however, it requires a NorthwindEmployee parameter to insert the data. For this reason, the collection of strings that the DetailsView control passes automatically is not sufficient. The NorthwindEmployeeInserting delegate is an ObjectDataSourceMethodEventHandler object that handles the Inserting event and enables you to manipulate the input parameters before the Insert operation proceeds. Because the UpdateEmployeeInfo method requires a NorthwindEmployee object as a parameter, one is created using the collection of strings and is added to the InputParameters collection.

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB" Assembly="Samples.AspNet.VB" %>
<%@ Import namespace="Samples.AspNet.VB" %>
<%@ Page language="vb" %>
<Script runat="server">
Private Sub NorthwindEmployeeInserting(source As Object, e As ObjectDataSourceMethodEventArgs)

  ' The GridView control passes an array of strings in the parameters
  ' collection because that is the type it knows how to work with.
  ' However, the business object expects a custom type. Build it
  ' and add it to the parameters collection.
  Dim paramsFromPage As IDictionary = e.InputParameters

  Dim ne As New NorthwindEmployee()
  ne.FirstName  = paramsFromPage("FirstName").ToString()
  ne.LastName   = paramsFromPage("LastName").ToString()
  ne.Title      = paramsFromPage("Title").ToString()
  ne.Courtesy   = paramsFromPage("Courtesy").ToString()
  ne.Supervisor = Int32.Parse(paramsFromPage("Supervisor").ToString())
  
  paramsFromPage.Clear()
  paramsFromPage.Add("ne", ne)
End Sub ' NorthwindEmployeeInserting

</Script>
<html>
  <head>
    <title>ObjectDataSource - VB Example</title>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">

        <asp:detailsview
          id="DetailsView1"
          runat="server"
          autogenerateinsertbutton="True"
          datasourceid="ObjectDataSource1">
        </asp:detailsview>

        <asp:objectdatasource
          id="ObjectDataSource1"
          runat="server"
          selectmethod="GetEmployee"
          insertmethod="UpdateEmployeeInfo"
          oninserting="NorthwindEmployeeInserting"
          typename="Samples.AspNet.VB.EmployeeLogic" >
          <selectparameters>
            <asp:parameter name="anID" defaultvalue="-1" />
          </selectparameters>
        </asp:objectdatasource>

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

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.JSL" Assembly="Samples.AspNet.JSL" %>
<%@ Import namespace="Samples.AspNet.JSL" %>
<%@ Page language="VJ#" %>
<Script runat="server">
private void NorthwindEmployeeInserting(Object source,
    ObjectDataSourceMethodEventArgs e)
{
    // The GridView control passes an array of strings in the parameters
    // collection because that is the type it knows how to work with.
    // However, the business object expects a custom type. Build it
    // and add it to the parameters collection.
    IDictionary paramsFromPage = e.get_InputParameters();

    NorthwindEmployee ne =  new NorthwindEmployee();
    ne.set_FirstName(paramsFromPage.get_Item("FirstName").ToString());
    ne.set_LastName (paramsFromPage.get_Item("LastName").ToString());
    ne.set_Title(paramsFromPage.get_Item("Title").ToString());
    ne.set_Courtesy(paramsFromPage.get_Item("Courtesy").ToString());
    ne.set_Supervisor(Int32.Parse(paramsFromPage.
        get_Item("Supervisor").ToString()));

    paramsFromPage.Clear();
    paramsFromPage.Add("ne", ne);
}

</Script>
<html>
  <head>
    <title>ObjectDataSource - VJ# Example</title>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">

        <asp:detailsview
          id="DetailsView1"
          runat="server"
          autogenerateinsertbutton="True"
          datasourceid="ObjectDataSource1">
        </asp:detailsview>

        <asp:objectdatasource
          id="ObjectDataSource1"
          runat="server"
          selectmethod="GetEmployee"
          insertmethod="UpdateEmployeeInfo"
          oninserting="NorthwindEmployeeInserting"
          typename="Samples.AspNet.JSL.EmployeeLogic" >
          <selectparameters>
            <asp:parameter name="anID" defaultvalue="-1" />
          </selectparameters>
        </asp:objectdatasource>

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

The following code example provides an example middle-tier business object that the preceding code example uses. The following list describes the two major classes that are defined in the code example:

  • The EmployeeLogic class, which is a stateless class that encapsulates business logic.

  • The NorthwindEmployee class, which is a model class that contains only the basic functionality that is required to load and persist data from the data tier.

In addition, a NorthwindDataException class is provided as a convenience.

This set of example classes uses the Northwind Traders database, which is an example database available with Microsoft SQL Server and Microsoft Access. For a complete working example, use these classes by placing them in the App_Code directory under the application root or by compiling them and placing the resulting DLL in the Bin directory. The UpdateEmployeeInfo method is not completely implemented, so you will not insert data into the Northwind Traders database when you experiment with this example.

Imports System
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

   ' Returns a collection of NorthwindEmployee objects.
   Public Shared Function GetAllEmployees() As ICollection

      Dim al As New ArrayList()

      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
      If anID.Equals("-1") OrElse anID.Equals(DBNull.Value) Then
         Return New NorthwindEmployee()
      Else
         Return New NorthwindEmployee(anID)
      End If
   End Function 'GetEmployee


   Public Shared Sub UpdateEmployeeInfo(ne As NorthwindEmployee)
      Dim retval As Boolean = ne.Save()
      If Not retval Then
         Throw New NorthwindDataException("UpdateEmployee failed.")
      End If
   End Sub 'UpdateEmployeeInfo

   Public Shared Sub DeleteEmployee(ne As NorthwindEmployee)
      Dim retval As Boolean = ne.Delete()
      If Not retval Then
         Throw New NorthwindDataException("DeleteEmployee failed.")
      End If
   End Sub 'DeleteEmployee

   ' And so on...

End Class 'EmployeeLogic


Public Class NorthwindEmployee


   Public Sub New()
      ID = DBNull.Value
      lastName = ""
      firstName = ""
      title = ""
      titleOfCourtesy = ""
      reportsTo = - 1
   End Sub 'New


   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,Title,TitleOfCourtesy,ReportsTo " & _
                               " 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()

         ' Only loop 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()
            Me.aTitle = sdr("Title").ToString()
            Me.titleOfCourtesy = sdr("TitleOfCourtesy").ToString()
            If Not sdr.IsDBNull(4) Then
               Me.reportsTo = sdr.GetInt32(4)
            End If
         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 'New

   Private ID As Object
   Public ReadOnly Property EmpID() As String
      Get
         Return ID.ToString()
      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 ReadOnly Property FullName() As String
      Get
         Return FirstName & " " & LastName
      End Get
   End Property

   Private aTitle As String
   Public Property Title() As String
      Get
         Return aTitle
      End Get
      Set
         aTitle = value
      End Set
   End Property

   Private titleOfCourtesy As String
   Public Property Courtesy() As String
      Get
         Return titleOfCourtesy
      End Get
      Set
         titleOfCourtesy = value
      End Set
   End Property

   Private reportsTo As Integer
   Public Property Supervisor() As Integer
      Get
         Return reportsTo
      End Get
      Set
         reportsTo = value
      End Set
   End Property

   Public Function Save() As Boolean

      ' Implement persistence logic.
      Return True

   End Function 'Save


   Public Function Delete() As Boolean

     ' Implement delete logic.
     Return True

   End Function 'Delete
End Class 'NorthwindEmployee


Friend Class NorthwindDataException
   Inherits Exception

   Public Sub New(msg As String)
      MyBase.New(msg)
   End Sub 'New
End Class 'NorthwindDataException

End Namespace

package  Samples.AspNet.JSL;

import System.*;
import System.Collections.*;
import System.Configuration.*;
import System.Data.*;
import System.Data.SqlClient.*;
import System.Web.UI.*;
import 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() throws
        NorthwindDataException, SqlException
    {
        ArrayList al =  new ArrayList();

		ConnectionStringSettings cts = 
			ConfigurationManager.get_ConnectionStrings().
			get_Item("NorthwindConnection");
			//ConfigurationSettings.get_ConnectionStrings().get_Item("NorthwindConnection");

        SqlDataSource sds = new SqlDataSource(cts.get_ConnectionString(),
            "SELECT EmployeeID FROM Employees");
        try { 
            IEnumerable ids = sds.Select(DataSourceSelectArguments.get_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 = (DataRowView) enumerator.get_Current();
                String id = row.get_Item("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;
    } //GetAllEmployees

    public static NorthwindEmployee GetEmployee(Object anId) throws 
        NorthwindDataException, SqlException
    {
        if (anId.Equals("-1") || anId.Equals(DBNull.Value)) {
            return new NorthwindEmployee();
        }
        else {
            return new NorthwindEmployee(anId);
        }
    } //GetEmployee

    public static void UpdateEmployeeInfo(NorthwindEmployee ne) throws 
        NorthwindDataException
    {
        boolean retval = ne.Save();
        if (!retval) {
            throw new NorthwindDataException("UpdateEmployee failed.");
        }
    } //UpdateEmployeeInfo

    public static void DeleteEmployee(NorthwindEmployee ne) throws 
        NorthwindDataException
    {
        boolean retval = ne.Delete();
        if (!retval) {
            throw new NorthwindDataException("DeleteEmployee failed.");
        }
    } //DeleteEmployee

    // And so on...
} //EmployeeLogic
   
public class NorthwindEmployee 
{
    public NorthwindEmployee() 
    {
        id = DBNull.Value;
        lastName = "";
        firstName = "";
        title = "";
        titleOfCourtesy = "";
        reportsTo =-1;
    } //NorthwindEmployee

    public NorthwindEmployee(Object anId) throws 
        NorthwindDataException ,SqlException
    {
        this.id = anId;
			

		SqlConnection conn = new SqlConnection(ConfigurationManager.
			get_ConnectionStrings().get_Item("NorthwindConnection").get_ConnectionString());
         SqlCommand sc =  new SqlCommand(
            " SELECT FirstName,LastName,Title,TitleOfCourtesy,ReportsTo " 
            + " FROM Employees WHERE EmployeeID = @empId", conn);
         // Add the employee id parameter and set its value.
         sc.get_Parameters().Add(new SqlParameter("@empId", SqlDbType.Int)).
             set_Value(anId.ToString());
         SqlDataReader sdr = null;
         
         try {
            conn.Open();
            sdr = sc.ExecuteReader();
            // Only loop once.
            if (sdr  != null && sdr.Read()) {
                // The IEnumerable contains DataRowView objects.
                this.firstName = sdr.get_Item( "FirstName").ToString();
                this.lastName = sdr.get_Item( "LastName").ToString();
                this.title = sdr.get_Item( "Title").ToString();
                this.titleOfCourtesy = sdr.get_Item( "TitleOfCourtesy").
                    ToString();
                if (!(sdr.IsDBNull(4))) {
                    this.reportsTo = sdr.GetInt32(4);
                }
            }
            else {
                throw new NorthwindDataException(
                    "Data not loaded for employee id.");
            }
        }
        finally {
            try {
                if (sdr != null) {
                    sdr.Close();
                }
                conn.Close();
            }
            catch(SqlException exp){   
            // Log an event in the Application Event Log.
            throw exp;
            }
        }
    } //NorthwindEmployee
      
    private Object id;
     
    /** @property 
     */
    public String get_EmpID()
    {
        return id.ToString();
    } //get_EmpID

    private String lastName;
      
      /** @property 
       */
    public String get_LastName()
    {
        return lastName;
    } //get_LastName

    /** @property 
     */
    public void set_LastName (String value)
    {
        lastName = value;
    } //set_LastName

    private String firstName;
      
    /** @property 
     */
    public String get_FirstName()
    {
        return firstName;
    } //get_FirstName

    /** @property 
     */
    public void set_FirstName (String value)
    {
        firstName = value;
    } //set_FirstName 

    /** @property 
     */
    public String get_FullName()
    {
        return get_FirstName() + " " + get_LastName();
    } //get_FullName

    private String title;
      
    /** @property 
     */
    public String get_Title()
    {
        return title;
    } //get_Title

    /** @property 
     */
    public void set_Title (String value)
    {
        title = value;
    } //set_Title 

    private String titleOfCourtesy;
      
    /** @property 
     */
    public String get_Courtesy()
    {
        return titleOfCourtesy;
    } //get_Courtesy

    /** @property 
     */
    public void set_Courtesy (String value)
    {
        titleOfCourtesy = value;
    } //set_Courtesy 

    private int reportsTo;
      
    /** @property 
     */
    public int get_Supervisor()
    {
        return reportsTo;
    }//get_Supervisor

    /** @property 
     */
    public void set_Supervisor (int value)
    {
        reportsTo = value;
    } //set_Supervisor 

    public boolean Save() 
    {
        // Implement persistence logic.
        return true;
    } //Save
      
    public boolean Delete() 
    {
        // Implement delete logic.
        return true;
    } //Delete
} //NorthwindEmployee

public class NorthwindDataException extends System.Exception
{
    public NorthwindDataException(String msg)
    {
         super(msg);
    } //NorthwindDataException
} //NorthwindDataException

  • AspNetHostingPermission  for operating in a hosted environment. Demand value: LinkDemand; Permission value: Minimal.
  • AspNetHostingPermission  for operating in a hosted environment. Demand value: InheritanceDemand; Permission value: Minimal.

System.Object
   System.EventArgs
     System.ComponentModel.CancelEventArgs
      System.Web.UI.WebControls.ObjectDataSourceMethodEventArgs
         System.Web.UI.WebControls.ObjectDataSourceSelectingEventArgs

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0

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