SqlDataSourceCommandEventArgs SqlDataSourceCommandEventArgs SqlDataSourceCommandEventArgs SqlDataSourceCommandEventArgs Class

Definizione

Fornisce i dati per gli eventi Updating, Deleting e Inserting del controllo SqlDataSource.Provides data for the Updating, Deleting and Inserting events of the SqlDataSource control.

public ref class SqlDataSourceCommandEventArgs : System::ComponentModel::CancelEventArgs
public class SqlDataSourceCommandEventArgs : System.ComponentModel.CancelEventArgs
type SqlDataSourceCommandEventArgs = class
    inherit CancelEventArgs
Public Class SqlDataSourceCommandEventArgs
Inherits CancelEventArgs
Ereditarietà
SqlDataSourceCommandEventArgsSqlDataSourceCommandEventArgsSqlDataSourceCommandEventArgsSqlDataSourceCommandEventArgs
Derivato

Esempi

Nell'esempio di codice riportato di seguito viene illustrato come visualizzare i dati recuperati da DropDownList un database di Microsoft SQL Server in un controllo e TextBox come aggiornare il record utilizzando un controllo.The following code example demonstrates how to display data retrieved from a Microsoft SQL Server database in a DropDownList control, and update the record using a TextBox control. Nell'esempio viene illustrato come è possibile utilizzare DbTransaction un oggetto per aggiungere il contesto di transazione SqlDataSource quando si utilizza il controllo per aggiornare i dati.The example shows how you can use a DbTransaction object to add transaction context when using the SqlDataSource control to update data.

<%@Page  Language="C#" %>
<%@Import Namespace="System.Data" %>
<%@Import Namespace="System.Data.Common" %>
<%@Import Namespace="System.Data.SqlClient" %>
<%@Import Namespace="System.Diagnostics" %>
<!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 On_Click(Object source, EventArgs e) {    
    SqlDataSource1.Update();
 }

 private void OnSqlUpdating(Object source, SqlDataSourceCommandEventArgs e) {
    DbCommand command = e.Command;
    DbConnection cx  = command.Connection;    
    cx.Open();    
    DbTransaction tx = cx.BeginTransaction();
    command.Transaction = tx;
 }

 private void OnSqlUpdated(Object source, SqlDataSourceStatusEventArgs e) {
    DbCommand command = e.Command;
    DbTransaction tx = command.Transaction;
    
    // In this code example the OtherProcessSucceeded variable represents
    // the outcome of some other process that occurs whenever the data is 
    // updated, and must succeed for the data change to be committed. For 
    // simplicity, we set this value to true. 
    bool OtherProcessSucceeded = true;
    
    if (OtherProcessSucceeded) {
        tx.Commit();
        Label2.Text="The record was updated successfully!";
    }
    else {
        tx.Rollback();
        Label2.Text="The record was not updated.";
    }
 }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="form1" runat="server">
      <asp:SqlDataSource
          id="SqlDataSource1"
          runat="server"
          ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
          SelectCommand="SELECT EmployeeID, LastName, Address FROM Employees"
          UpdateCommand="UPDATE Employees SET Address=@Address WHERE EmployeeID=@EmployeeID"
          OnUpdating="OnSqlUpdating"
          OnUpdated ="OnSqlUpdated">
          <UpdateParameters>
              <asp:ControlParameter Name="Address" ControlId="TextBox1" PropertyName="Text"/>
              <asp:ControlParameter Name="EmployeeID" ControlId="DropDownList1" PropertyName="SelectedValue"/>
          </UpdateParameters>
      </asp:SqlDataSource>

      <asp:DropDownList
          id="DropDownList1"
          runat="server"
          DataTextField="LastName"
          DataValueField="EmployeeID"
          DataSourceID="SqlDataSource1">
      </asp:DropDownList>

      <br />
      <asp:Label id="Label1" runat="server" Text="Enter a new address for the selected user."
        AssociatedControlID="TextBox1" />
      <asp:TextBox id="TextBox1" runat="server" />
      <asp:Button id="Submit" runat="server" Text="Submit" OnClick="On_Click" />

      <br /><asp:Label id="Label2" runat="server" Text="" />

    </form>
  </body>
</html>
<%@Page  Language="VB" %>
<%@Import Namespace="System.Data" %>
<%@Import Namespace="System.Data.Common" %>
<%@Import Namespace="System.Diagnostics" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

 Sub On_Click(ByVal source As Object, ByVal e As EventArgs)
        SqlDataSource1.Update()
 End Sub 'On_Click

 Sub On_Sql_Updating(ByVal source As Object, ByVal e As SqlDataSourceCommandEventArgs)
     Dim command as DbCommand
     Dim connection as DbConnection
     Dim transaction as DbTransaction
     
     command    = e.Command
     connection = command.Connection     
     connection.Open()     
     transaction = connection.BeginTransaction()
     command.Transaction = transaction
 
 End Sub 'On_Sql_Updating
 
 Sub On_Sql_Updated(ByVal source As Object, ByVal e As SqlDataSourceStatusEventArgs)
 
    Dim command As DbCommand
    Dim transaction As DbTransaction
    
    command = e.Command
    transaction = command.Transaction
    
    ' In this code example the OtherProcessSucceeded variable represents
    ' the outcome of some other process that occurs whenever the data is 
    ' updated, and must succeed for the data change to be committed. For 
    ' simplicity, we set this value to true. 
    Dim OtherProcessSucceeded as Boolean = True
    
    If (OtherProcessSucceeded) Then
        transaction.Commit()
        Label2.Text="The record was updated successfully!"
    Else    
        transaction.Rollback()
        Label2.Text="The record was not updated."
    End If
 End Sub ' On_Sql_Updated
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="form1" runat="server">
      <asp:SqlDataSource
          id="SqlDataSource1"
          runat="server"
          ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
          SelectCommand="SELECT EmployeeID, LastName, Address FROM Employees"
          UpdateCommand="UPDATE Employees SET Address=@Address WHERE EmployeeID=@EmployeeID"
          OnUpdating="On_Sql_Updating"
          OnUpdated ="On_Sql_Updated">
          <UpdateParameters>
              <asp:ControlParameter Name="Address" ControlId="TextBox1" PropertyName="Text"/>
              <asp:ControlParameter Name="EmployeeID" ControlId="DropDownList1" PropertyName="SelectedValue"/>
          </UpdateParameters>
      </asp:SqlDataSource>

      <asp:DropDownList
          id="DropDownList1"
          runat="server"
          DataTextField="LastName"
          DataValueField="EmployeeID"
          DataSourceID="SqlDataSource1">
      </asp:DropDownList>

      <br />
      <asp:Label id="Label1" runat="server" Text="Enter a new address for the selected user."
        AssociatedControlID="TextBox1" />
      <asp:TextBox id="TextBox1" runat="server" />
      <asp:Button id="Submit" runat="server" Text="Submit" OnClick="On_Click" />

      <br /><asp:Label id="Label2" runat="server" Text="" />

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

Commenti

Se si aggiunge un delegato del gestore eventi per Updatinggestire Insertinggli eventi Deleting , o, è possibile eseguire qualsiasi operazione di pre-elaborazione aggiuntiva o annullare completamente il comando del database.By adding an event handler delegate to handle the Updating, Inserting, or Deleting events, you can perform any additional preprocessing required or cancel the database command entirely.

Poiché la SqlDataSourceCommandEventArgs classe è derivata CancelEventArgs dalla classe, è SqlDataSource possibile annullare un comando di database in sospeso impostando la Cancel proprietà su true.Because the SqlDataSourceCommandEventArgs class is derived from the CancelEventArgs class, you can cancel a pending SqlDataSource database command by setting the Cancel property to true. È possibile esaminare e modificare le CommandTextproprietà Parameters , raccolta e altre proprietà del comando prima di eseguire il comando accedendo Command all' DbCommand oggetto esposto dalla proprietà.You can examine and manipulate the CommandText, Parameters collection, and other command properties prior to running the command by accessing the DbCommand object exposed by the Command property.

La SqlDataSourceCommandEventArgs classe viene utilizzata OnUpdatingnei metodi, OnInsertinge OnDeleting per consentire l'accesso a un SqlDataSource comando di database prima dell'esecuzione.The SqlDataSourceCommandEventArgs class is used in the OnUpdating, OnInserting, and OnDeleting methods to provide access to a SqlDataSource database command before it is run. Il SqlDataSource controllo espone molti eventi che è possibile gestire per lavorare con gli oggetti dati sottostanti nel corso di un'operazione sui dati.The SqlDataSource control exposes many events that you can handle to work with the underlying data objects during the course of a data operation. La tabella seguente elenca gli eventi e le EventArgs classi di gestori eventi e associati, per migliorare la guida ai vari eventi che corrispondono al ciclo di vita di un'operazione sui SqlDataSource dati tramite il controllo.The following table lists the events and associated EventArgs and event handler classes, to better guide you to the various events that correspond to the lifecycle of a data operation using the SqlDataSource control.

eventEvent EventArgsEventArgs EventHandlerEventHandler
Selectingsi verifica prima che vengano recuperati i dati.Selecting occurs before the data is retrieved. SqlDataSourceSelectingEventArgs SqlDataSourceSelectingEventHandler
Inserting, Updating ,Deleting si verificano prima dell'esecuzione di un'operazione di inserimento, aggiornamento o eliminazione.Inserting, Updating, Deleting occur before an insert, update, or delete operation is performed. SqlDataSourceCommandEventArgs SqlDataSourceCommandEventHandler
Selected, Inserted, Updated ,Deleted si verificano dopo il completamento delle operazioni di recupero, inserimento, aggiornamento o eliminazione dei dati.Selected, Inserted, Updated, Deleted occur after the data retrieval, insert, update, or delete operations completes. SqlDataSourceStatusEventArgs SqlDataSourceStatusEventHandler

Costruttori

SqlDataSourceCommandEventArgs(DbCommand) SqlDataSourceCommandEventArgs(DbCommand) SqlDataSourceCommandEventArgs(DbCommand) SqlDataSourceCommandEventArgs(DbCommand)

Inizializza una nuova istanza della classe SqlDataSourceCommandEventArgs con l'oggetto comando di database specificato.Initializes a new instance of the SqlDataSourceCommandEventArgs class, using the specified database command object.

Proprietà

Cancel Cancel Cancel Cancel

Ottiene o imposta un valore che indica se l'evento debba essere annullato.Gets or sets a value indicating whether the event should be canceled.

(Inherited from CancelEventArgs)
Command Command Command Command

Ottiene il comando di database in sospeso.Gets the pending database command.

Metodi

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Determina se l'oggetto specificato è uguale all'oggetto corrente.Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Funge da funzione hash predefinita.Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

Ottiene l'oggetto Type dell'istanza corrente.Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Crea una copia superficiale dell'oggetto Object corrente.Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

Restituisce una stringa che rappresenta l'oggetto corrente.Returns a string that represents the current object.

(Inherited from Object)

Si applica a

Vedi anche