SqlConnectionStringBuilder.AsynchronousProcessing Eigenschaft

Definition

Ruft einen booleschen Wert ab, der angibt, ob die mit dieser Verbindungszeichenfolge erstellte Verbindung eine asynchrone Verarbeitung zulässt.Gets or sets a Boolean value that indicates whether asynchronous processing is allowed by the connection created by using this connection string.

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

Eigenschaftswert

Der Wert der AsynchronousProcessing-Eigenschaft oder false, wenn kein Wert angegeben wurde.The value of the AsynchronousProcessing property, or false if no value has been supplied.

Beispiele

Im folgenden Beispiel wird eine Verbindungszeichenfolge abgerufen und überprüft, ob die Verbindungszeichenfolge so konfiguriert ist, dass asynchrone Verarbeitung zulässig ist.The following example retrieves a connection string and verifies that the connection string is configured to allow for asynchronous processing. (In diesem Fall stammt die Zeichenfolge aus einer Prozedur innerhalb der Anwendung, doch in einer Produktionsanwendung stammt die Verbindungszeichenfolge möglicherweise aus einer Konfigurationsdatei oder einer anderen Quelle.) Anschließend wird im Beispiel ein asynchroner Vorgang ausgeführt, wobei Werte in einer Beispieldatenbank in einem Hintergrundthread aktualisiert werden.(In this case, the string comes from a procedure within the application, but in a production application, the connection string might come from a configuration file, or some other source.) Then, the example performs an asynchronous operation, updating values within a sample database on a background thread.

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

Hinweise

Diese Eigenschaft entspricht den Schlüsseln "Asynchrone Verarbeitung" und "async" in der Verbindungszeichenfolge.This property corresponds to the "Asynchronous Processing" and "async" keys within the connection string. Um die asynchrone Verarbeitung zu nutzen, die vom SqlCommand-Objekt bereitgestellt wird, muss dieses Schlüssel-Wert-Paar in die Verbindungszeichenfolge des zugehörigen SqlConnection-Objekts eingeschlossen werden.In order to take advantage of the asynchronous processing provided by the SqlCommand object, this key/value pair must be included within the connection string of the associated SqlConnection object.

Gilt für:

Siehe auch