ObjectDataSource.Inserting ObjectDataSource.Inserting ObjectDataSource.Inserting ObjectDataSource.Inserting Event

Definition

Tritt vor einem Insert()-Vorgang ein.Occurs before an Insert() operation.

public:
 event System::Web::UI::WebControls::ObjectDataSourceMethodEventHandler ^ Inserting;
public event System.Web.UI.WebControls.ObjectDataSourceMethodEventHandler Inserting;
member this.Inserting : System.Web.UI.WebControls.ObjectDataSourceMethodEventHandler 
Public Custom Event Inserting As ObjectDataSourceMethodEventHandler 

Beispiele

Dieser Abschnitt enthält zwei Codebeispiele.This section contains two code examples. Im ersten Codebeispiel wird veranschaulicht, wie ein ObjectDataSource -Objekt mit einem Geschäftsobjekt und DetailsView ein-Steuerelement zum Einfügen von Daten verwendet wird.The first code example demonstrates how to use an ObjectDataSource object with a business object and a DetailsView control to insert data. Das zweite Codebeispiel enthält ein Beispiel für das Geschäftsobjekt der mittleren Ebene, das im ersten Codebeispiel verwendet wird.The second code example provides an example of the middle-tier business object that is used in the first code example.

Im folgenden Codebeispiel wird veranschaulicht, wie ein ObjectDataSource -Steuerelement mit einem Geschäftsobjekt DetailsView und einem-Steuerelement zum Einfügen von Daten verwendet wird.The following code example demonstrates how to use an ObjectDataSource control with a business object and a DetailsView control to insert data. Zuerst wird ein neuer NorthwindEmployee Datensatz **** angezeigt,zusammenmiteinerautomatischgeneriertenSchaltflächeDetailsView einfügen.Initially, the DetailsView displays a new NorthwindEmployee record, along with an automatically generated Insert button. Nachdem Sie Daten in die Felder des DetailsView -Steuer Elements eingegeben haben, klicken Sie auf die Schaltfläche Einfügen .After you enter data into the fields of the DetailsView control, click the Insert button. Die InsertMethod -Eigenschaft identifiziert, welche Methode den Einfügevorgang ausführt.The InsertMethod property identifies which method performs the insert operation.

In diesem Beispiel wird die UpdateEmployeeInfo -Methode verwendet, um eine Einfügung auszuführen, erfordert jedoch einen NorthwindEmployee -Parameter, um die Daten einzufügen.In this example, the UpdateEmployeeInfo method is used to perform an insert; however, it requires a NorthwindEmployee parameter to insert the data. Aus diesem Grund ist die Auflistung von Zeichen folgen, DetailsView die das Steuerelement automatisch übergibt, nicht ausreichend.For this reason, the collection of strings that the DetailsView control passes automatically is not sufficient. Der NorthwindEmployeeInserting Delegat ist ObjectDataSourceMethodEventHandler ein Objekt, das Inserting das-Ereignis behandelt und es Ihnen ermöglicht, die Eingabe Insert Parameter zu bearbeiten, bevor der Vorgang fortgesetzt wird.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. Da die UpdateEmployeeInfo Methode ein NorthwindEmployee -Objekt als Parameter erfordert, wird eine mithilfe der Auflistung von Zeichen folgen erstellt und der InputParameters -Auflistung mithilfe eines Parameter namens (ne) hinzugefügt, der von der-Methode erwartet wird.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 using a parameter name (ne) that the method expects. Sie können wie folgt Verfahren ausführen, wenn Sie ein vorhandenes Objekt der mittleren Ebene als Datenquelle mit Typen und Methoden verwenden, die nicht speziell für die Verwendung ObjectDataSource mit dem Steuerelement entworfen wurden.You might perform steps like these when using an existing middle-tier object as a data source with types and methods that are not designed specifically for use with the ObjectDataSource control.

Wenn der Insert Vorgang ausgeführt wird, wird die durch die InsertMethod -Eigenschaft identifizierte Methode aufgerufen.When the Insert operation is performed, the method that is identified by the InsertMethod property is called. Wenn die Insert -Methode des-Objekts über eine Methoden Signatur verfügt, die Parameter InsertParameters enthält, muss die Auflistung einen Parameter mit Namen enthalten, die den Methoden Signatur Insert Parametern entsprechen, damit die Methode erfolgreich abgeschlossen werden kann.If the Insert method of the object has a method signature that includes parameters, the InsertParameters collection must contain a parameter with names that match the method signature parameters for the Insert method to complete successfully.

<%@ 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 NorthwindEmployeeInserting(object source, ObjectDataSourceMethodEventArgs e)
{
  // The business object expects a custom type. Build it
  // and add it to the parameters collection.
  
  IDictionary paramsFromPage = e.InputParameters;

  NorthwindEmployee ne = 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);
}

</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: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.CS.EmployeeLogic"
          >
          <selectparameters>
            <asp:parameter name="anID" defaultvalue="-1" />
          </selectparameters>
        </asp:objectdatasource>

    </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">
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 xmlns="http://www.w3.org/1999/xhtml" >
  <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>

Das folgende Codebeispiel enthält ein Beispiel für ein Geschäftsobjekt der mittleren Ebene, das im vorangehenden Codebeispiel verwendet wird.The following code example provides an example of a middle-tier business object that the preceding code example uses. Das Codebeispiel besteht aus zwei grundlegenden Klassen:The code example consists of two basic classes:

  • Die EmployeeLogic -Klasse, die eine Zustands lose Klasse ist, die Geschäftslogik kapselt.The EmployeeLogic class, which is a stateless class that encapsulates business logic.

  • Die NorthwindEmployee -Klasse, bei der es sich um eine Modell Klasse handelt, die nur die grundlegenden Funktionen enthält, die zum Laden und Speichern von Daten aus der Datenebene erforderlich sind.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.

Eine zusätzliche NorthwindDataException Klasse wird zur einfacheren Bereitstellung bereitgestellt.An additional NorthwindDataException class is provided as a convenience. Ein umfassendes, funktionierendes Beispiel ist die Kompilierung und Verwendung dieser Klassen.For a complete working example, you must compile and use these classes. Die UpdateEmployeeInfo -Methode ist nicht vollständig implementiert, sodass Sie keine Daten in die Northwind Traders-Datenbank einfügen, wenn Sie mit diesem Beispiel experimentieren.The UpdateEmployeeInfo method is not completely implemented, so you will not insert data into the Northwind Traders database when you experiment with this 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();

      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) {
      if (anID.Equals("-1") ||
          anID.Equals(DBNull.Value) ) {
        return new NorthwindEmployee();
      }
      else {
        return new NorthwindEmployee(anID);
      }
    }

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

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

    // And so on...
  }

  public class NorthwindEmployee {

    public NorthwindEmployee () {
      ID = DBNull.Value;
      lastName = "";
      firstName = "";
      title="";
      titleOfCourtesy = "";
      reportsTo = -1;
    }

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

      SqlConnection conn
        = new SqlConnection (ConfigurationManager.ConnectionStrings["NorthwindConnection"].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.Parameters.Add(new SqlParameter("@empId",SqlDbType.Int)).Value = Int32.Parse(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["FirstName"].ToString();
          this.lastName         = sdr["LastName"].ToString();
          this.title            = sdr["Title"].ToString();
          this.titleOfCourtesy  = sdr["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) {
          // Log an event in the Application Event Log.
          throw;
        }
      }
    }

    private object ID;
    public string EmpID {
      get { return ID.ToString();  }
    }

    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 string FullName {
      get { return FirstName + " " + LastName; }
    }

    private string title;
    public String Title {
      get { return title; }
      set { title = value; }
    }

    private string titleOfCourtesy;
    public string Courtesy {
      get { return titleOfCourtesy; }
      set { titleOfCourtesy = value; }
    }

    private int    reportsTo;
    public int Supervisor {
      get { return reportsTo; }
      set { reportsTo = value; }
    }

    public bool Save () {
      // Implement persistence logic.
      return true;
    }

    public bool Delete () {
      // Implement delete logic.
      return true;
    }
  }

  internal 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

   ' 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

Hinweise

Behandeln Sie Inserting das-Ereignis, um zusätzliche Initialisierungen auszuführen, die für Ihre Anwendung spezifisch sind, um die Werte von Parametern zu überprüfen oder um ObjectDataSource die Parameterwerte zu ändern, bevor das-Steuerelement den Einfügevorgang ausführtHandle the Inserting event to perform additional initialization that is specific to your application, to validate the values of parameters, or to change the parameter values before the ObjectDataSource control performs the insert operation. Die Parameter sind als eine IDictionary Auflistung verfügbar, auf die von der InputParameters -Eigenschaft zugegriffen wird, die durch das ObjectDataSourceMethodEventArgs -Objekt verfügbar gemacht wird.The parameters are available as an IDictionary collection that is accessed by the InputParameters property, which is exposed by the ObjectDataSourceMethodEventArgs object.

Weitere Informationen zum Behandeln von Ereignissen finden Sie unter behandeln und Auslösen von Ereignissen.For more information about how to handle events, see Handling and Raising Events.

Gilt für:

Siehe auch