Deriving from WebResponse

Article
10/17/2014

The WebResponse class is an abstract base class that provides the basic methods and properties for creating a protocol-specific response that fits the .NET Framework pluggable protocol model. Applications that use the WebRequest class to request data from resources receive the responses in a WebResponse. Protocol-specific WebResponse descendants must implement the abstract members of the WebResponse class.

The associated WebRequest class must create WebResponse descendants. For example, HttpWebResponse instances are created only as the result of calling HttpWebRequest.GetResponse or HttpWebRequest.EndGetResponse. Each WebResponse contains the result of a request to a resource and is not intended to be reused.

ContentLength Property

The ContentLength property indicates the number of bytes of data that are available from the stream returned by the GetResponseStream method. The ContentLength property does not indicate the number of bytes of header or metadata information returned by the server; it indicates only the number of bytes of data in the requested resource itself.

ContentType Property

The ContentType property provides any special information that your protocol requires you to send to the client to identify the type of content being sent by the server. Typically this is the MIME content type of any data returned.

Headers Property

The Headers property contains an arbitrary collection of name/value pairs of metadata associated with the response. Any metadata needed by the protocol that can be expressed as a name/value pair can be included in the Headers property.

You are not required to use the Headers property to use header metadata. Protocol-specific metadata can be exposed as properties; for example, the HttpWebResponse.LastModified property exposes the Last-Modified HTTP header. When you expose header metadata as a property, you should not allow the same property to be set using the Headers property.

ResponseUri Property

The ResponseUri property contains the URI of the resource that actually provided the response. For protocols that do not support redirection, ResponseUri will be the same as the RequestUri property of the WebRequest that created the response. If the protocol supports redirecting the request, ResponseUri will contain the URI of the response.

Close Method

The Close method closes any connections made by the request and response and cleans up resources used by the response. The Close method closes any stream instances used by the response, but it does not throw an exception if the response stream was previously closed by a call to the Stream.Close method.

GetResponseStream Method

The GetResponseStream method returns a stream containing the response from the requested resource. The response stream contains only the data returned by the resource; any header or metadata included in the response should be stripped from the response and exposed to the application through protocol-specific properties or the Headers property.

The stream instance returned by the GetResponseStream method is owned by the application and can be closed without closing the WebResponse. By convention, calling the WebResponse.Close method also closes the stream returned by GetResponse.

Partager via