SqlConnectionStringBuilder.AsynchronousProcessing Propriété

public:
 property bool AsynchronousProcessing { bool get(); void set(bool value); };

public bool AsynchronousProcessing { get; set; }

member this.AsynchronousProcessing : bool with get, set

Public Property AsynchronousProcessing As Boolean

Valeur de propriété

Valeur de la propriété AsynchronousProcessing ou false si aucune valeur n’a été fournie.

Exemples

L'exemple suivant récupère une chaîne de connexion et vérifie que la chaîne de connexion est configurée pour autoriser le traitement asynchrone. (Dans ce cas, la chaîne provient d’une procédure au sein de l’application, mais dans une application de production, le chaîne de connexion peut provenir d’un fichier de configuration ou d’une autre source.) Ensuite, l’exemple effectue une opération asynchrone, en mettant à jour les valeurs dans un exemple de base de données sur un thread d’arrière-plan.

using System.Data.SqlClient;
using System.Threading;

class Program
{
    static void Main()
    {
        // Create a SqlConnectionStringBuilder instance,
        // and ensure that it is set up for asynchronous processing.
        SqlConnectionStringBuilder builder =
            new SqlConnectionStringBuilder(GetConnectionString());
        // Asynchronous method calls won't work unless you
        // have added this option, or have added
        // the clause "Asynchronous Processing=true"
        // to the connection string.
        builder.AsynchronousProcessing = true;

        string commandText =
            "UPDATE Production.Product SET ReorderPoint = ReorderPoint + 1 " +
            "WHERE ReorderPoint IS NOT Null;" +
            "WAITFOR DELAY '0:0:3';" +
            "UPDATE Production.Product SET ReorderPoint = ReorderPoint - 1 " +
            "WHERE ReorderPoint IS NOT Null";
        RunCommandAsynchronously(commandText, builder.ConnectionString);

        Console.WriteLine("Press any key to finish.");
        Console.ReadLine();
    }

    private static string GetConnectionString()
    {
        // To avoid storing the connection string in your code,
        // you can retrieve it from a configuration file.
        return "Data Source=(local);Integrated Security=SSPI;" +
            "Initial Catalog=AdventureWorks";
    }

    private static void RunCommandAsynchronously(string commandText,
        string connectionString)
    {
        // Given command text and connection string, asynchronously execute
        // the specified command against the connection. For this example,
        // the code displays an indicator as it's working, verifying the
        // asynchronous behavior.
        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            try
            {
                int count = 0;
                SqlCommand command = new SqlCommand(commandText, connection);
                connection.Open();
                IAsyncResult result = command.BeginExecuteNonQuery();
                while (!result.IsCompleted)
                {
                    Console.WriteLine("Waiting {0}.", count);
                    // Wait for 1/10 second, so the counter
                    // doesn't consume all available resources
                    // on the main thread.
                    Thread.Sleep(100);
                    count += 1;
                }
                Console.WriteLine("Command complete. Affected {0} rows.",
                    command.EndExecuteNonQuery(result));
            }
            catch (SqlException ex)
            {
                Console.WriteLine(
                    "Error {0}: System.Data.SqlClient.SqlConnectionStringBuilder",
                    ex.Number, ex.Message);
            }
            catch (InvalidOperationException ex)
            {
                Console.WriteLine("Error: {0}", ex.Message);
            }
            catch (Exception ex)
            {
                // You might want to pass these errors
                // back out to the caller.
                Console.WriteLine("Error: {0}", ex.Message);
            }
        }
    }
}

Imports System.Data.SqlClient
Imports System.Threading


Module Module1
    Sub Main()
        ' Create a SqlConnectionStringBuilder instance, 
        ' and ensure that it is set up for asynchronous processing.
        Dim builder As _
         New SqlConnectionStringBuilder(GetConnectionString())
        ' Asynchronous method calls won't work unless you
        ' have added this option, or have added
        ' the clause "Asynchronous Processing=True"
        ' to the connection string.
        builder.AsynchronousProcessing = True

        Dim commandText As String = _
         "UPDATE Production.Product SET ReorderPoint = ReorderPoint + 1 " & _
         "WHERE ReorderPoint Is Not Null;" & _
         "WAITFOR DELAY '0:0:3';" & _
         "UPDATE Production.Product SET ReorderPoint = ReorderPoint - 1 " & _
         "WHERE ReorderPoint Is Not Null"
        RunCommandAsynchronously(commandText, builder.ConnectionString)

        Console.WriteLine("Press any key to finish.")
        Console.ReadLine()
    End Sub

    Private Function GetConnectionString() As String
        ' To avoid storing the connection string in your code,
        ' you can retrieve it from a configuration file. 
        Return "Data Source=(local);Integrated Security=SSPI;" & _
          "Initial Catalog=AdventureWorks"
    End Function

    Private Sub RunCommandAsynchronously( _
     ByVal commandText As String, ByVal connectionString As String)

        ' Given command text and connection string, asynchronously execute
        ' the specified command against the connection. For this example,
        ' the code displays an indicator as it's working, verifying the 
        ' asynchronous behavior. 
        Using connection As New SqlConnection(connectionString)
            Try
                Dim count As Integer = 0
                Dim command As New SqlCommand(commandText, connection)
                connection.Open()
                Dim result As IAsyncResult = command.BeginExecuteNonQuery()
                While Not result.IsCompleted
                    Console.WriteLine("Waiting {0}.", count)
                    ' Wait for 1/10 second, so the counter
                    ' doesn't consume all available resources 
                    ' on the main thread.
                    Threading.Thread.Sleep(100)
                    count += 1
                End While
                Console.WriteLine("Command complete. Affected {0} rows.", _
                    command.EndExecuteNonQuery(result))
            Catch ex As SqlException
                Console.WriteLine( _
                "Error {0}: System.Data.SqlClient.SqlConnectionStringBuilder", _
                ex.Number, ex.Message)
            Catch ex As InvalidOperationException
                Console.WriteLine("Error: {0}", ex.Message)
            Catch ex As Exception
                ' You might want to pass these errors
                ' back out to the caller.
                Console.WriteLine("Error: {0}", ex.Message)
            End Try
        End Using
    End Sub
End Module

Remarques

Cette propriété correspond aux clés « Asynchronous Processing » et « async » dans la chaîne de connexion. Pour tirer parti du traitement asynchrone fourni par l'objet SqlCommand, cette paire clé/valeur doit être incluse dans la chaîne de connexion de l'objet SqlConnection associé.

S’applique à

Voir aussi

• BeginExecuteReader()
• BeginExecuteNonQuery()
• BeginExecuteXmlReader()
• Chaînes de connexion dans ADO.NET
• Vue d'ensemble d’ADO.NET