A long containing the number of bytes returned from the resource.
Type Reason NotSupportedException This property is not implemented in the derived class.
The WebResponse.ContentLength property contains the length, in bytes, of the response from the Internet resource. For request methods that contain header information, the WebResponse.ContentLength does not include the length of the header information.
The System.Net.WebResponse class is an abstract class. The actual behavior of System.Net.WebResponse instances at run time is determined by the descendant class returned by WebRequest.GetResponse. For more information about default values and exceptions, please see the documentation for the descendant classes, such as System.Net.HttpWebResponse and System.Net.FileWebResponse.