HttpListenerRequest.UrlReferrer HttpListenerRequest.UrlReferrer HttpListenerRequest.UrlReferrer HttpListenerRequest.UrlReferrer Property

Definition

Ruft den URI (Uniform Resource Identifier) der Ressource ab, die den Client an den Server verwiesen hat.Gets the Uniform Resource Identifier (URI) of the resource that referred the client to the server.

public:
 property Uri ^ UrlReferrer { Uri ^ get(); };
public Uri UrlReferrer { get; }
member this.UrlReferrer : Uri
Public ReadOnly Property UrlReferrer As Uri

Eigenschaftswert

Ein Uri-Objekt, das den Text des Referer-Headers der Anforderung enthält, oder null, wenn der Header nicht in die Anforderung eingefügt wurde.A Uri object that contains the text of the request's Referer header, or null if the header was not included in the request.

Beispiele

Im folgenden Codebeispiel wird die Verwendung dieser Eigenschaft veranschaulicht.The following code example demonstrates using this property.

public static void ShowRequestProperties1 (HttpListenerRequest request)
{
    // Display the MIME types that can be used in the response.
    string[] types = request.AcceptTypes;
    if (types != null)
    {
        Console.WriteLine("Acceptable MIME types:");
        foreach (string s in types)
        {
            Console.WriteLine(s);
        }
    }
    // Display the language preferences for the response.
    types = request.UserLanguages;
    if (types != null)
    {
        Console.WriteLine("Acceptable natural languages:");
        foreach (string l in types)
        {
            Console.WriteLine(l);
        }
    }
    
    // Display the URL used by the client.
    Console.WriteLine("URL: {0}", request.Url.OriginalString);
    Console.WriteLine("Raw URL: {0}", request.RawUrl);
    Console.WriteLine("Query: {0}", request.QueryString);

    // Display the referring URI.
    Console.WriteLine("Referred by: {0}", request.UrlReferrer);

    //Display the HTTP method.
    Console.WriteLine("HTTP Method: {0}", request.HttpMethod);
    //Display the host information specified by the client;
    Console.WriteLine("Host name: {0}", request.UserHostName);
    Console.WriteLine("Host address: {0}", request.UserHostAddress);
    Console.WriteLine("User agent: {0}", request.UserAgent);
}
Public Shared Sub ShowRequestProperties1(ByVal request As HttpListenerRequest)
    ' Display the MIME types that can be used in the response.
    Dim types As String() = request.AcceptTypes

    If types IsNot Nothing Then
        Console.WriteLine("Acceptable MIME types:")

        For Each s As String In types
            Console.WriteLine(s)
        Next
    End If

    ' Display the language preferences for the response.
    types = request.UserLanguages

    If types IsNot Nothing Then
        Console.WriteLine("Acceptable natural languages:")

        For Each l As String In types
            Console.WriteLine(l)
        Next
    End If

    ' Display the URL used by the client.
    Console.WriteLine("URL: {0}", request.Url.OriginalString)
    Console.WriteLine("Raw URL: {0}", request.RawUrl)
    Console.WriteLine("Query: {0}", request.QueryString)

    ' Display the referring URI.
    Console.WriteLine("Referred by: {0}", request.UrlReferrer)

    ' Display the HTTP method.
    Console.WriteLine("HTTP Method: {0}", request.HttpMethod)

    ' Display the host information specified by the client.
    Console.WriteLine("Host name: {0}", request.UserHostName)
    Console.WriteLine("Host address: {0}", request.UserHostAddress)
    Console.WriteLine("User agent: {0}", request.UserAgent)
End Sub

Hinweise

Wenn ein Client einen Hyperlink zum angeforderten URI befolgt hat, enthält die Anforderung möglicherweise einen Referrer Header, der den URI der Ressource identifiziert, die den Hyperlink enthielt.If a client has followed a hyperlink to the requested URI, its request might contain a Referrer header that identifies the URI of the resource that contained the hyperlink.

Clients können eine Referer Kopfzeile fälschen oder nicht angeben.Clients can falsify or choose not to present a Referer header. Daher kann die UrlReferrer -Eigenschaft nützlich sein, um grundlegende Trends im Webdatenverkehr zu identifizieren. Sie sollten Sie nicht als Teil eines Autorisierungs Schemas verwenden, um den Zugriff auf Daten zu steuern.Therefore, while the UrlReferrer property can be useful for identifying basic trends in Web traffic; you should not use it as part of an authorization scheme to control access to data.

Eine umfassende Liste mit Anforderungs Headern finden Sie unter HttpRequestHeader der-Enumeration.For a complete list of request headers, see the HttpRequestHeader enumeration.

Der UrlReferrer ist NULL, wenn in der Referrer Anforderung kein-Header vorhanden ist oder Referrer wenn der-Header in der Anforderung vorhanden ist, jedoch nicht in einen Urigültigen-Wert analysiert wird.The UrlReferrer is null when there is no Referrer header in the request or when the Referrer header is present in the request but does not parse to a valid Uri.

Gilt für:

Siehe auch