HttpListenerResponse.KeepAlive Eigenschaft

  • Referenz

Definition

Namespace:
System.Net
Assembly:
System.Net.HttpListener.dll
Assembly:
System.dll
Assembly:
netstandard.dll
Quelle:
HttpListenerResponse.cs
Quelle:
HttpListenerResponse.cs
Quelle:
HttpListenerResponse.cs

Ruft einen Wert ab, der angibt, ob der Server eine permanente Verbindung anfordert, oder legt diesen fest.

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

Eigenschaftswert

Boolean

true, wenn der Server eine permanente Verbindung anfordert, andernfalls false. Der Standardwert ist true.

Ausnahmen

ObjectDisposedException

Dieses Objekt ist geschlossen.

Beispiele

Im folgenden Codebeispiel wird das Festlegen des Werts dieser Eigenschaft veranschaulicht.


// 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)

Hinweise

Wenn ein HTTP-Client und ein HTTP-Server erwarten, daten mehrmals in kurzer Zeit auszutauschen, beschleunigt eine permanente Verbindung die Kommunikation, indem sie den Mehraufwand vermeiden können, der zum Öffnen und Schließen einer TCP-Verbindung für jede Nachricht erforderlich ist. Persistente Verbindungen werden in der Kommunikation zwischen modernen Webbrowsern und Webservern häufig verwendet.

Persistente Verbindungen werden ausführlich in der HTTP/1.1-Protokollspezifikation (RFC 2616) beschrieben, die auf der RTF-Editor-Website (https://www.rfc-editor.org/) verfügbar ist.

Gilt für:

Weitere Informationen