HttpListenerRequest.ContentLength64 Property    
Definition
Important
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Gets the length of the body data included in the request.
public:
 property long ContentLength64 { long get(); };
	public long ContentLength64 { get; }
	member this.ContentLength64 : int64
	Public ReadOnly Property ContentLength64 As Long
	Property Value
The value from the request's Content-Length header. This value is -1 if the content length is not known.
Examples
The following code example uses the ContentLength64 property while processing body data.
public static void ShowRequestData (HttpListenerRequest request)
{
    if (!request.HasEntityBody)
    {
        Console.WriteLine("No client data was sent with the request.");
        return;
    }
    System.IO.Stream body = request.InputStream;
    System.Text.Encoding encoding = request.ContentEncoding;
    System.IO.StreamReader reader = new System.IO.StreamReader(body, encoding);
    if (request.ContentType != null)
    {
        Console.WriteLine("Client data content type {0}", request.ContentType);
    }
    Console.WriteLine("Client data content length {0}", request.ContentLength64);
    Console.WriteLine("Start of client data:");
    // Convert the data to a string and display it on the console.
    string s = reader.ReadToEnd();
    Console.WriteLine(s);
    Console.WriteLine("End of client data:");
    body.Close();
    reader.Close();
    // If you are finished with the request, it should be closed also.
}
Public Shared Sub ShowRequestData(ByVal request As HttpListenerRequest)
    If Not request.HasEntityBody Then
        Console.WriteLine("No client data was sent with the request.")
        Return
    End If
    Dim body As System.IO.Stream = request.InputStream
    Dim encoding As System.Text.Encoding = request.ContentEncoding
    Dim reader As System.IO.StreamReader = New System.IO.StreamReader(body, encoding)
    If request.ContentType IsNot Nothing Then
        Console.WriteLine("Client data content type {0}", request.ContentType)
    End If
    Console.WriteLine("Client data content length {0}", request.ContentLength64)
    Console.WriteLine("Start of client data:")
    ' Convert the data to a string and display it on the console.
    Dim s As String = reader.ReadToEnd()
    Console.WriteLine(s)
    Console.WriteLine("End of client data:")
    body.Close()
    reader.Close()
    ' If you are finished with the request, it should be closed also.
End Sub
	Remarks
The Content-Length header expresses the length, in bytes, of the body data that accompanies the request.
For a complete list of request headers, see the HttpRequestHeader enumeration.