SqlRowUpdatingEventArgs Classe

Definizione

public ref class SqlRowUpdatingEventArgs sealed : System::Data::Common::RowUpdatingEventArgs

public sealed class SqlRowUpdatingEventArgs : System.Data.Common.RowUpdatingEventArgs

type SqlRowUpdatingEventArgs = class
    inherit RowUpdatingEventArgs

Public NotInheritable Class SqlRowUpdatingEventArgs
Inherits RowUpdatingEventArgs

Ereditarietà

Object

EventArgs

RowUpdatingEventArgs

SqlRowUpdatingEventArgs

Esempio

Nell'esempio seguente viene illustrato come usare gli RowUpdating eventi e RowUpdated .

L'evento RowUpdating restituisce questo output:

argomenti dell'evento: (command=System.Data.SqlClient.SQLCommand commandType=2 status=0)

L'evento RowUpdated restituisce questo output:

event args: (command=System.Data.SqlClient.SQLCommand commandType=2 recordsAffected=1 row=System.Data.DataRow[37] status=0)

// handler for RowUpdating event
private static void OnRowUpdating(object sender, SqlRowUpdatingEventArgs e)
{
    PrintEventArgs(e);
}

//Handler for RowUpdated event.
private static void OnRowUpdated(object sender, SqlRowUpdatedEventArgs e)
{
    PrintEventArgs(e);
}

public static int Main()
{
    const string CONNECTION_STRING = "Persist Security Info=False;Integrated Security=SSPI;database=northwind;server=mySQLServer";
    const string SELECT_ALL = "select * from Products";

    //Create DataAdapter.
    SqlDataAdapter rAdapter    = new SqlDataAdapter(SELECT_ALL, CONNECTION_STRING);

    //Create and fill DataSet (Select only first 5 rows.).
    DataSet rDataSet = new DataSet();
    rAdapter.Fill(rDataSet, 0, 5, "Table");

    //Modify DataSet.
    DataTable rTable = rDataSet.Tables["Table"];
    rTable.Rows[0][1] = "new product";

    //Add handlers.
    rAdapter.RowUpdating += new SqlRowUpdatingEventHandler( OnRowUpdating );
    rAdapter.RowUpdated += new SqlRowUpdatedEventHandler( OnRowUpdated );

    //Update--this operation fires two events (RowUpdating and RowUpdated) for each changed row.
    rAdapter.Update(rDataSet, "Table");

    //Remove handlers.
    rAdapter.RowUpdating -= new SqlRowUpdatingEventHandler( OnRowUpdating );
    rAdapter.RowUpdated -= new SqlRowUpdatedEventHandler( OnRowUpdated );
    return 0;
}

private static void PrintEventArgs(SqlRowUpdatingEventArgs args)
{
    Console.WriteLine("OnRowUpdating");
    Console.WriteLine("  event args: ("+
        " command=" + args.Command +
        " commandType=" + args.StatementType +
        " status=" + args.Status + ")");
}

private static void PrintEventArgs(SqlRowUpdatedEventArgs args)
{
    Console.WriteLine("OnRowUpdated");
    Console.WriteLine("  event args: ("+
        " command=" + args.Command +
        " commandType=" + args.StatementType +
        " recordsAffected=" + args.RecordsAffected +
        " status=" + args.Status + ")");
}

'Handler for RowUpdating event.
Private Shared Sub OnRowUpdating(sender As Object, e As SqlRowUpdatingEventArgs)
    PrintEventArgs(e)
End Sub 

'Handler for RowUpdated event.
Private Shared Sub OnRowUpdated(sender As Object, e As SqlRowUpdatedEventArgs)
    PrintEventArgs(e)
End Sub 

'Entry point which delegates to C-style main Private Function.
Public Overloads Shared Sub Main()
    System.Environment.ExitCode = Main(System.Environment.GetCommandLineArgs())
End Sub

Overloads Public Shared Function Main(args() As String) As Integer
    Const CONNECTION_STRING As String = "Persist Security Info=False;Integrated Security=SSPI;database=northwind;server=mySQLServer"
    Const SELECT_ALL As String = "select * from Products"
    
    'Create DataAdapter.
    Dim rAdapter As New SqlDataAdapter(SELECT_ALL, CONNECTION_STRING)
    
    'Create and fill DataSet (Select only first 5 rows.).
    Dim rDataSet As New DataSet()
    rAdapter.Fill(rDataSet, 0, 5, "Table")
    
    'Modify DataSet.
    Dim rTable As DataTable = rDataSet.Tables("Table")
    rTable.Rows(0)(1) = "new product"
    
    'Add handlers.
    AddHandler rAdapter.RowUpdating, AddressOf OnRowUpdating
    AddHandler rAdapter.RowUpdated, AddressOf OnRowUpdated
    
    'Update--this operation fires two events (RowUpdating and RowUpdated) for each changed row. 
    rAdapter.Update(rDataSet, "Table")
    
    'Remove handlers.
    RemoveHandler rAdapter.RowUpdating, AddressOf OnRowUpdating
    RemoveHandler rAdapter.RowUpdated, AddressOf OnRowUpdated
    Return 0
End Function 

Overloads Private Shared Sub PrintEventArgs(args As SqlRowUpdatingEventArgs)
    Console.WriteLine("OnRowUpdating")
    Console.WriteLine("  event args: (" & _
                    " command=" & _
                    args.Command.CommandText & _
                    " commandType=" & _
                    args.StatementType & _
                    " status=" & _
                    args.Status & _
                    ")")
End Sub 


Overloads Private Shared Sub PrintEventArgs(args As SqlRowUpdatedEventArgs)
    Console.WriteLine("OnRowUpdated")
    Console.WriteLine("  event args: (" & _
                    " command=" & _
                    args.Command.CommandText & _
                    " commandType=" & _
                    args.StatementType & _
                    " recordsAffected=" & _
                    args.RecordsAffected & _
                    " status=" & _
                    args.Status & _
                    ")")
End Sub

Commenti

L'evento RowUpdating viene generato prima Update di una riga.

Quando si usa Update, sono presenti due eventi che si verificano per ogni riga di dati aggiornata. L'ordine di esecuzione è il seguente:

1. I valori in DataRow vengono spostati nei valori dei parametri.

2. Viene generato l'evento OnRowUpdating.

3. Il comando viene eseguito.

4. Se il comando è impostato su FirstReturnedRecorde il primo risultato restituito viene inserito in DataRow.

5. Se sono presenti parametri di output, vengono inseriti in DataRow.

6. Viene generato l'evento OnRowUpdated.

7. Chiamata del metodo AcceptChanges.

Costruttori

Proprietà

Metodi

Si applica a

Vedi anche

• Panoramica di ADO.NET