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HttpListenerResponse.KeepAlive Propriété

  • Référence

Définition

Espace de noms:
System.Net
Assembly:
System.Net.HttpListener.dll
Assembly:
System.dll
Assembly:
netstandard.dll
Source:
HttpListenerResponse.cs
Source:
HttpListenerResponse.cs
Source:
HttpListenerResponse.cs

Obtient ou définit une valeur indiquant si le serveur exige une connexion persistante.

public:
 property bool KeepAlive { bool get(); void set(bool value); };
public bool KeepAlive { get; set; }
member this.KeepAlive : bool with get, set
Public Property KeepAlive As Boolean

Valeur de propriété

Boolean

true si le serveur exige une connexion persistante ; sinon, false. La valeur par défaut est true.

Exceptions

ObjectDisposedException

Cet objet est fermé.

Exemples

L’exemple de code suivant illustre la définition de la valeur de cette propriété.


// When the client is not authenticated, there is no Identity.
if (context.User == null)
{
    message.Append ("<HTML><BODY><p> Hello local user! </p></BODY></HTML>");
}
else
{
    // Get the requester's identity.
    System.Security.Principal.WindowsIdentity identity = WindowsIdentity.GetCurrent();
    // Construct the response body.
    message.AppendFormat ("<HTML><BODY><p> Hello {0}!<br/>",
        identity.Name);
    message.AppendFormat ("You were authenticated using {0}.</p>",
        identity.AuthenticationType);
    message.Append ("</BODY></HTML>");
}

// Configure the response.
HttpListenerResponse response = context.Response;

// Use the encoding from the response if one has been set.
// Otherwise, use UTF8.
System.Text.Encoding encoding = response.ContentEncoding;
if (encoding == null)
{
    encoding = System.Text.Encoding.UTF8;
    response.ContentEncoding = encoding;
}
byte[] buffer = encoding.GetBytes (message.ToString ());
response.ContentLength64 = buffer.Length;
response.StatusCode = (int) HttpStatusCode.OK;
response.StatusDescription = "OK";
response.ProtocolVersion = new Version ("1.1");
// Don't keep the TCP connection alive;
// We don't expect multiple requests from the same client.
response.KeepAlive = false;
// Write the response body.
System.IO.Stream stream = response.OutputStream;
stream.Write(buffer, 0, buffer.Length);


' When the client is not authenticated, there is no Identity.
If context.User Is Nothing Then
    message.Append("<HTML><BODY><p> Hello local user! </p></BODY></HTML>")
Else
    ' Get the requester's identity.
    Dim identity As System.Security.Principal.WindowsIdentity = WindowsIdentity.GetCurrent()
    ' Construct the response body.
    message.AppendFormat("<HTML><BODY><p> Hello {0}!<br/>", identity.Name)
    message.AppendFormat("You were authenticated using {0}.</p>", identity.AuthenticationType)
    message.Append("</BODY></HTML>")
End If

' Configure the response.
Dim response As HttpListenerResponse = context.Response

' Use the encoding from the response if one has been set.
' Otherwise, use UTF8.
Dim encoding As System.Text.Encoding = response.ContentEncoding
If encoding Is Nothing Then
    encoding = System.Text.Encoding.UTF8
    response.ContentEncoding = encoding
End If
Dim buffer() As Byte = encoding.GetBytes(message.ToString())
response.ContentLength64 = buffer.Length
response.StatusCode = CInt(HttpStatusCode.OK)
response.StatusDescription = "OK"
response.ProtocolVersion = New Version("1.1")
' Don't keep the TCP connection alive
' We don't expect multiple requests from the same client.
response.KeepAlive = False
' Write the response body.
Dim stream As System.IO.Stream = response.OutputStream
stream.Write(buffer, 0, buffer.Length)

Remarques

Si un client et un serveur HTTP s’attendent à échanger des données plusieurs fois dans un court laps de temps, une connexion persistante accélère leurs communications en leur permettant d’éviter la surcharge requise pour ouvrir et fermer une connexion TCP pour chaque message. Les connexions persistantes sont largement utilisées dans les communications entre les navigateurs Web modernes et les serveurs Web.

Les connexions persistantes sont décrites en détail dans la spécification du protocole HTTP/1.1 (RFC 2616) disponible sur le site Web de l’éditeur RTF (https://www.rfc-editor.org/).

S’applique à

Voir aussi