ObjectDataSourceMethodEventArgs 类

定义

Inserting 控件的 UpdatingDeletingObjectDataSource 事件提供数据。Provides data for the Inserting, Updating, and Deleting events of the ObjectDataSource control.

public ref class ObjectDataSourceMethodEventArgs : System::ComponentModel::CancelEventArgs
public class ObjectDataSourceMethodEventArgs : System.ComponentModel.CancelEventArgs
type ObjectDataSourceMethodEventArgs = class
    inherit CancelEventArgs
Public Class ObjectDataSourceMethodEventArgs
Inherits CancelEventArgs
继承
ObjectDataSourceMethodEventArgs
派生

示例

本部分包含两个代码示例。This section contains two code examples. 第一个代码示例演示如何将ObjectDataSource控件与业务对象DetailsView和控件结合使用来插入数据。The first code example demonstrates how to use an ObjectDataSource control with a business object and a DetailsView control to insert data. 第二个代码示例提供了第一个代码示例使用的中间层业务对象示例。The second code example provides an example middle-tier business object that is used by the first code example.

下面的代码示例演示如何将ObjectDataSource控件与业务对象DetailsView和控件结合使用来插入数据。The following code example demonstrates how to use an ObjectDataSource control with a business object and a DetailsView control to insert data. 最初显示一个新NorthwindEmployee记录以及自动生成的 "插入" 按钮。 DetailsViewThe DetailsView initially displays a new NorthwindEmployee record, along with an automatically generated Insert button. DetailsView数据输入到控件的字段中后, 单击 "插入" 按钮, 该InsertMethod Insert属性将确定执行该操作的方法。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.

在此示例中, UpdateEmployeeInfo方法用于执行插入; 但是, 它需要一个NorthwindEmployee参数来插入数据。In this example, the UpdateEmployeeInfo method is used to perform an insert; however, it requires a NorthwindEmployee parameter to insert the data. 出于此原因, DetailsView控件自动传递的字符串集合是不够的。For this reason, the collection of strings that the DetailsView control passes automatically is not sufficient. 委托是处理Inserting事件并使Insert你能够在操作继续之前操作输入参数的对象。ObjectDataSourceMethodEventHandler NorthwindEmployeeInsertingThe NorthwindEmployeeInserting delegate is an ObjectDataSourceMethodEventHandler object that handles the Inserting event and enables you to manipulate the input parameters before the Insert operation proceeds. 由于方法需要对象作为参数, 因此使用字符串集合创建一个对象, InputParameters并将其添加到集合中。 NorthwindEmployee UpdateEmployeeInfoBecause 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.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>

下面的代码示例提供了前面的代码示例使用的中间层业务对象示例。The following code example provides an example middle-tier business object that the preceding code example uses. 下面的列表描述了代码示例中定义的两个主要类:The following list describes the two major classes that are defined in the code example:

  • EmployeeLogic类, 该类是封装业务逻辑的无状态类。The EmployeeLogic class, which is a stateless class that encapsulates business logic.

  • NorthwindEmployee类, 该类是一个模型类, 其中只包含从数据层加载和保存数据所需的基本功能。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.

此外, 还提供NorthwindDataException了一个方便的类。In addition, a NorthwindDataException class is provided as a convenience.

这组示例类使用 Northwind 商贸数据库, 这是一个可用于 Microsoft SQL Server 和 Microsoft Access 的示例数据库。This set of example classes uses the Northwind Traders database, which is an example database available with Microsoft SQL Server and Microsoft Access. 若要获取完整的工作示例, 请使用这些类, 方法是将它们放在应用程序根目录下的 App_Code 目录中, 或者通过编译它们并将生成的 DLL 放入 Bin 目录中。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. UpdateEmployeeInfo方法未完全实现, 因此当您试验此示例时, 不会将数据插入 Northwind 商贸数据库中。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

   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

   ' And so on...

End Class


Public Class NorthwindEmployee


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

   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


Friend Class NorthwindDataException
   Inherits Exception

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

End Namespace

注解

OnUpdating Select Update类在、 、OnInsertingDelete方法中使用, 以提供对传递到、、和的输入参数的访问。 OnDeleting ObjectDataSourceMethodEventArgs OnSelecting Insert控件ObjectDataSource的方法。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. 使用InputParameters属性访问这些参数。These parameters are accessed using the InputParameters property. 通过添加委托来Selecting处理、 UpdatingInsertingDeleting事件, 可以检查和操作参数的值, 并执行所需的任何其他预处理。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. 对此字典中的参数所做的任何更改都将影响为该操作调用的方法重载。Any changes to the parameters in this dictionary will affect which method overload is called for the operation. 如果设置DataObjectTypeNameObjectDataSource控件的属性, 则只能修改此字典中项的数据对象属性, 而不能添加或移除参数。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. 有关详细信息,请参阅 DeleteFor more information, see Delete.

ObjectDataSource控件公开了许多事件, 您可以处理这些事件, 以便在其生命周期中的不同时间使用基础业务对象。The ObjectDataSource control exposes many events that you can handle to work with the underlying business object at various times in its life cycle. 下表列出了事件和关联EventArgs的类以及事件处理程序委托。The following table lists the events and associated EventArgs classes and event handler delegates.

事件Event EventArgsEventArgs class EventHandler 委托EventHandler delegate
ObjectCreatingObjectCreating.

在创建业务对象的实例之前立即发生。Occurs immediately before the instance of the business object is created.
ObjectDataSourceEventArgs ObjectDataSourceObjectEventHandler
ObjectCreatedObjectCreated.

在创建业务对象的实例之后立即发生。Occurs immediately after the instance of the business object is created.
ObjectDataSourceEventArgs ObjectDataSourceObjectEventHandler
SelectingSelecting.

在检索数据之前发生。Occurs before the data is retrieved.
ObjectDataSourceSelectingEventArgs ObjectDataSourceSelectingEventHandler
InsertingUpdatingDeletingInserting, Updating, and Deleting.

在执行插入、更新或删除操作之前发生。Occur before an insert, update, or delete operation is performed.
ObjectDataSourceMethodEventArgs ObjectDataSourceMethodEventHandler
SelectedSelected.

在检索数据后发生。Occurs after the data is retrieved.
ObjectDataSourceStatusEventArgs ObjectDataSourceStatusEventHandler
InsertedUpdatedDeletedInserted, Updated, and Deleted.

完成插入、更新或删除操作后发生。Occur after the insert, update, or delete operation is completed.
ObjectDataSourceStatusEventArgs ObjectDataSourceStatusEventHandler
ObjectDisposingObjectDisposing.

在销毁业务对象之前发生。Occurs before a business object is destroyed.
ObjectDataSourceDisposingEventArgs ObjectDataSourceDisposingEventHandler

构造函数

ObjectDataSourceMethodEventArgs(IOrderedDictionary)

使用指定的输入参数集合初始化 ObjectDataSourceMethodEventArgs 类的新实例。Initializes a new instance of the ObjectDataSourceMethodEventArgs class using the specified input parameters collection.

属性

Cancel

获取或设置指示是否应取消事件的值。Gets or sets a value indicating whether the event should be canceled.

(继承自 CancelEventArgs)
InputParameters

获取包含业务对象方法参数及其值的集合。Gets a collection that contains business object method parameters and their values.

方法

Equals(Object)

确定指定的对象是否等于当前对象。Determines whether the specified object is equal to the current object.

(继承自 Object)
GetHashCode()

用作默认哈希函数。Serves as the default hash function.

(继承自 Object)
GetType()

获取当前实例的 TypeGets the Type of the current instance.

(继承自 Object)
MemberwiseClone()

创建当前 Object 的浅表副本。Creates a shallow copy of the current Object.

(继承自 Object)
ToString()

返回一个表示当前对象的 string。Returns a string that represents the current object.

(继承自 Object)

适用于

另请参阅