ObjectDataSource.DeleteParameters Propriedade
Definição
Importante
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Obtém a coleção de parâmetros que contém os parâmetros usados pelo método DeleteMethod.
public:
property System::Web::UI::WebControls::ParameterCollection ^ DeleteParameters { System::Web::UI::WebControls::ParameterCollection ^ get(); };[System.Web.UI.PersistenceMode(System.Web.UI.PersistenceMode.InnerProperty)]
public System.Web.UI.WebControls.ParameterCollection DeleteParameters { get; }[<System.Web.UI.PersistenceMode(System.Web.UI.PersistenceMode.InnerProperty)>]
member this.DeleteParameters : System.Web.UI.WebControls.ParameterCollectionPublic ReadOnly Property DeleteParameters As ParameterCollectionValor da propriedade
Um ParameterCollection que contém os parâmetros usados pelo método DeleteMethod.
- Atributos
Exemplos
Esta seção contém dois exemplos de código. O primeiro exemplo de código demonstra como usar um ObjectDataSource objeto com um objeto de negócios e um GridView controle para excluir dados. O segundo exemplo de código mostra a EmployeeLogic classe usada no primeiro exemplo de código.
O exemplo de código a seguir demonstra como usar a DeleteParameters propriedade do ObjectDataSource controle com um objeto de negócios e um GridView controle para excluir dados. Inicialmente, o GridView controle exibe um conjunto de todos os funcionários, usando o método especificado pela SelectMethod propriedade para recuperar os dados do EmployeeLogic objeto . Como a AutoGenerateDeleteButton propriedade é definida como true, o GridView controle exibe automaticamente um botão Excluir .
Se você clicar no botão Excluir , o Deleting evento será chamado com dois parâmetros. Um parâmetro, EmpID, vem do DataGrid controle e é baseado na DataKeyNames propriedade . O outro parâmetro vem da propriedade declarativa DeleteParameters . A EmployeeLogic classe sobrecarrega o DeleteEmployee método . Uma sobrecarga usa um NorthwindEmployee parâmetro e a outra usa um Int32 parâmetro chamado anID. Deleting No caso, as entradas na InputParameters propriedade são ajustadas para incluir apenas um parâmetro chamado anID com o valor de original_EmpID. Quando o manipulador de eventos existe, o método correspondente DeleteEmployee é chamado.
O exemplo de código a seguir mostra a página da Web que exibe o DataGrid controle e manipula o Deleting evento.
<%@ 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)
{
IDictionary paramsFromPage = e.InputParameters;
paramsFromPage.Remove("anID");
paramsFromPage.Add("anID", (int)paramsFromPage["EmpID"]);
paramsFromPage.Remove("EmpID");
}
</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"
DataKeyNames="EmpID">
</asp:gridview>
<asp:objectdatasource
id="ObjectDataSource1"
runat="server"
selectmethod="GetAllEmployees"
deletemethod="DeleteEmployee"
OnDeleting="NorthwindEmployeeDeleting"
typename="Samples.AspNet.CS.EmployeeLogic">
<deleteparameters>
<asp:parameter name="anID" type="Int32" />
</deleteparameters>
</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 NorthwindEmployeeDeleting(source As Object, e As ObjectDataSourceMethodEventArgs)
Dim paramsFromPage As IDictionary = e.InputParameters
paramsFromPage.Remove("anID")
paramsFromPage.Add("anID", CInt(paramsFromPage("EmpID")))
paramsFromPage.Remove("EmpID")
End Sub ' NorthwindEmployeeDeleting
</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"
DataKeyNames="EmpID">
</asp:gridview>
<asp:objectdatasource
id="ObjectDataSource1"
runat="server"
selectmethod="GetAllEmployees"
deletemethod="DeleteEmployee"
OnDeleting="NorthwindEmployeeDeleting"
typename="Samples.AspNet.VB.EmployeeLogic">
<deleteparameters>
<asp:parameter name="anID" type="Int32" />
</deleteparameters>
</asp:objectdatasource>
</form>
</body>
</html>
O exemplo de código a seguir mostra a EmployeeLogic classe usada no exemplo de código anterior.
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;
int id = (int) row["EmployeeID"];
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(int 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 DeleteEmployee(int anID) {
NorthwindEmployee tempEmp = new NorthwindEmployee(anID);
DeleteEmployee(tempEmp);
}
}
public class NorthwindEmployee {
public NorthwindEmployee (int 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.DeleteCommand = "DELETE FROM Employees WHERE EmployeeID=@empID;";
sds.DeleteParameters.Add(new Parameter("empID",TypeCode.Int32,this.ID.ToString()));
/* To make this sample fully functional, uncomment these lines
int retval = sds.Delete();
if (retval == 1) { return true; }
return false; */
return true;
}
finally {
sds.Dispose();
}
}
}
}
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()
' 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(CInt(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 Integer) 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 DeleteEmployee(anID As Integer)
Dim tempEmp As New NorthwindEmployee(anID)
DeleteEmployee(tempEmp)
End Sub
' And so on...
End Class
Public Class NorthwindEmployee
Public Sub New(anID As Integer)
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.firstName = sdr("FirstName").ToString()
Me.lastName = 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.DeleteCommand = "DELETE FROM Employees WHERE EmployeeID=@empID;"
Dim param As New Parameter("empID", TypeCode.Int32, CStr(Me.ID))
sds.DeleteParameters.Add(param)
' To make this sample fully functional, uncomment these lines
' int retval = sds.Delete();
' if (retval == 1) { return true; }
' return false;
Return True
Finally
sds.Dispose()
End Try
End If
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
Comentários
Os nomes e tipos dos parâmetros contidos na DeleteParameters coleção devem corresponder aos nomes e tipos dos parâmetros na assinatura do DeleteMethod método. Os nomes de parâmetro são afetados pela OldValuesParameterFormatString propriedade e diferenciam maiúsculas de minúsculas. Os parâmetros na coleção dependem dos dados que estão no controle associado a dados, dos parâmetros especificados declarativamente e dos parâmetros adicionados programaticamente. Para obter mais informações, consulte "Mesclagem de parâmetros" em Delete e Usando parâmetros com o controle ObjectDataSource.
A DeleteParameters propriedade recupera a DeleteParameters propriedade contida pelo ObjectDataSourceView objeto associado ao ObjectDataSource controle .
Para obter mais informações sobre mesclagem de parâmetros, tempo de vida do objeto e resolução de método, consulte DeleteMethod.
Aplica-se a
Confira também
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