ObjectDataSource.Inserting Kejadian
Definisi
Penting
Beberapa informasi terkait produk prarilis yang dapat diubah secara signifikan sebelum dirilis. Microsoft tidak memberikan jaminan, tersirat maupun tersurat, sehubungan dengan informasi yang diberikan di sini.
Terjadi sebelum Insert() operasi.
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 Jenis Acara
Contoh
Bagian ini berisi dua contoh kode. Contoh kode pertama menunjukkan cara menggunakan ObjectDataSource objek dengan objek bisnis dan DetailsView kontrol untuk menyisipkan data. Contoh kode kedua memberikan contoh objek bisnis tingkat menengah yang digunakan dalam contoh kode pertama.
Contoh kode berikut menunjukkan cara menggunakan ObjectDataSource kontrol dengan objek bisnis dan DetailsView kontrol untuk menyisipkan data. Awalnya, DetailsView menampilkan rekaman baru NorthwindEmployee , bersama dengan tombol Sisipkan yang dihasilkan secara otomatis. Setelah Anda memasukkan data ke dalam bidang DetailsView kontrol, klik tombol Sisipkan . Properti InsertMethod mengidentifikasi metode mana yang melakukan operasi penyisipan.
Dalam contoh ini, UpdateEmployeeInfo metode ini digunakan untuk melakukan penyisipan; namun, memerlukan NorthwindEmployee parameter untuk menyisipkan data. Untuk alasan ini, pengumpulan string yang dilewati DetailsView kontrol secara otomatis tidak cukup. Delegasi NorthwindEmployeeInserting adalah ObjectDataSourceMethodEventHandler objek yang menangani Inserting peristiwa dan memungkinkan Anda memanipulasi parameter input sebelum Insert operasi dilanjutkan.
UpdateEmployeeInfo Karena metode memerlukan NorthwindEmployee objek sebagai parameter, seseorang dibuat menggunakan kumpulan string dan ditambahkan ke InputParameters koleksi menggunakan nama parameter (ne) yang diharapkan metode. Anda mungkin melakukan langkah-langkah seperti ini saat menggunakan objek tingkat menengah yang ada sebagai sumber data dengan jenis dan metode yang tidak dirancang khusus untuk digunakan dengan ObjectDataSource kontrol.
Insert Ketika operasi dilakukan, metode yang diidentifikasi oleh InsertMethod properti dipanggil.
Insert Jika metode objek memiliki tanda tangan metode yang menyertakan parameter, InsertParameters koleksi harus berisi parameter dengan nama yang cocok dengan parameter tanda tangan metode agar Insert metode berhasil diselesaikan.
<%@ 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>
Contoh kode berikut memberikan contoh objek bisnis tingkat menengah yang digunakan contoh kode sebelumnya. Contoh kode terdiri dari dua kelas dasar:
Kelas
EmployeeLogic, yang merupakan kelas stateless yang merangkum logika bisnis.Kelas
NorthwindEmployee, yang merupakan kelas model yang hanya berisi fungsionalitas dasar yang diperlukan untuk memuat dan mempertahankan data dari tingkat data.
Kelas tambahan NorthwindDataException disediakan sebagai kenyamanan. Untuk contoh kerja lengkap, Anda harus mengkompilasi dan menggunakan kelas-kelas ini. Metode UpdateEmployeeInfo ini tidak sepenuhnya diimplementasikan, jadi Anda tidak akan menyisipkan data ke dalam database Northwind Traders saat Anda bereksperimen dengan contoh ini.
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
Keterangan
Inserting Tangani peristiwa untuk melakukan inisialisasi tambahan yang khusus untuk aplikasi Anda, untuk memvalidasi nilai parameter, atau untuk mengubah nilai parameter sebelum ObjectDataSource kontrol melakukan operasi penyisipan. Parameter tersedia sebagai IDictionary koleksi yang diakses oleh InputParameters properti , yang diekspos oleh ObjectDataSourceMethodEventArgs objek .
Untuk informasi selengkapnya tentang cara menangani peristiwa, lihat Menangani dan Menaikkan Peristiwa.
