HttpWebRequest.GetResponse Method
Definition
Important
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Returns a response from an Internet resource.
public:
override System::Net::WebResponse ^ GetResponse();public override System.Net.WebResponse GetResponse ();override this.GetResponse : unit -> System.Net.WebResponsePublic Overrides Function GetResponse () As WebResponseReturns
A WebResponse that contains the response from the Internet resource.
Exceptions
The stream is already in use by a previous call to BeginGetResponse(AsyncCallback, Object).
-or-
TransferEncoding is set to a value and SendChunked is false.
Method is GET or HEAD, and either ContentLength is greater or equal to zero or SendChunked is true.
-or-
KeepAlive is true, AllowWriteStreamBuffering is false, ContentLength is -1, SendChunked is false, and Method is POST or PUT.
-or-
The HttpWebRequest has an entity body but the GetResponse() method is called without calling the GetRequestStream() method.
-or-
The ContentLength is greater than zero, but the application does not write all of the promised data.
The request cache validator indicated that the response for this request can be served from the cache; however, this request includes data to be sent to the server. Requests that send data must not use the cache. This exception can occur if you are using a custom cache validator that is incorrectly implemented.
Abort() was previously called.
-or-
The time-out period for the request expired.
-or-
An error occurred while processing the request.
Examples
The following code example gets the response for a request.
#using <System.dll>
using namespace System;
using namespace System::Net;
using namespace System::Text;
using namespace System::IO;
// Specify the URL to receive the request.
int main()
{
array<String^>^args = Environment::GetCommandLineArgs();
HttpWebRequest^ request = dynamic_cast<HttpWebRequest^>(WebRequest::Create(args[1]));
// Set some reasonable limits on resources used by this request
request->MaximumAutomaticRedirections = 4;
request->MaximumResponseHeadersLength = 4;
// Set credentials to use for this request.
request->Credentials = CredentialCache::DefaultCredentials;
HttpWebResponse^ response = dynamic_cast<HttpWebResponse^>(request->GetResponse());
Console::WriteLine("Content length is {0}", response->ContentLength);
Console::WriteLine("Content type is {0}", response->ContentType);
// Get the stream associated with the response.
Stream^ receiveStream = response->GetResponseStream();
// Pipes the stream to a higher level stream reader with the required encoding format.
StreamReader^ readStream = gcnew StreamReader(receiveStream, Encoding::UTF8);
Console::WriteLine("Response stream received.");
Console::WriteLine(readStream->ReadToEnd());
response->Close();
readStream->Close();
}
/*
The output from this example will vary depending on the value passed into Main
but will be similar to the following:
Content length is 1542
Content type is text/html; charset=utf-8
Response stream received.
<html>
...
</html>
*/
using System;
using System.Net;
using System.Text;
using System.IO;
public class Test
{
// Specify the URL to receive the request.
public static void Main (string[] args)
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(args[0]);
// Set some reasonable limits on resources used by this request
request.MaximumAutomaticRedirections = 4;
request.MaximumResponseHeadersLength = 4;
// Set credentials to use for this request.
request.Credentials = CredentialCache.DefaultCredentials;
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Console.WriteLine("Content length is {0}", response.ContentLength);
Console.WriteLine("Content type is {0}", response.ContentType);
// Get the stream associated with the response.
Stream receiveStream = response.GetResponseStream();
// Pipes the stream to a higher level stream reader with the required encoding format.
StreamReader readStream = new StreamReader(receiveStream, Encoding.UTF8);
Console.WriteLine("Response stream received.");
Console.WriteLine(readStream.ReadToEnd());
response.Close();
readStream.Close();
}
}
/*
The output from this example will vary depending on the value passed into Main
but will be similar to the following:
Content length is 1542
Content type is text/html; charset=utf-8
Response stream received.
<html>
...
</html>
*/
Imports System.Net
Imports System.Text
Imports System.IO
Public Class Test
' Specify the URL to receive the request.
Public Shared Sub Main(ByVal args() As String)
Dim request As HttpWebRequest = CType(WebRequest.Create(args(0)), HttpWebRequest)
' Set some reasonable limits on resources used by this request
request.MaximumAutomaticRedirections = 4
request.MaximumResponseHeadersLength = 4
' Set credentials to use for this request.
request.Credentials = CredentialCache.DefaultCredentials
Dim response As HttpWebResponse = CType(request.GetResponse(), HttpWebResponse)
Console.WriteLine("Content length is {0}", response.ContentLength)
Console.WriteLine("Content type is {0}", response.ContentType)
' Get the stream associated with the response.
Dim receiveStream As Stream = response.GetResponseStream()
' Pipes the stream to a higher level stream reader with the required encoding format.
Dim readStream As New StreamReader(receiveStream, Encoding.UTF8)
Console.WriteLine("Response stream received.")
Console.WriteLine(readStream.ReadToEnd())
response.Close()
readStream.Close()
End Sub
End Class
'
'The output from this example will vary depending on the value passed into Main
'but will be similar to the following:
'
'Content length is 1542
'Content type is text/html; charset=utf-8
'Response stream received.
'...
'
'
Remarks
Caution
WebRequest, HttpWebRequest, ServicePoint, and WebClient are obsolete, and you shouldn't use them for new development. Use HttpClient instead.
The GetResponse method returns a WebResponse object that contains the response from the Internet resource. The actual instance returned is an HttpWebResponse, and can be typecast to that class to access HTTP-specific properties.
A ProtocolViolationException is thrown in several cases when the properties set on the HttpWebRequest class are conflicting. This exception occurs if an application sets the ContentLength property and the SendChunked property to true, and then sends an HTTP GET request. This exception occurs if an application tries to send chunked to a server that only supports HTTP 1.0 protocol, where this is not supported. This exception occurs if an application tries to send data without setting the ContentLength property or the SendChunked is false when buffering is disabled and on a keepalive connection (the KeepAlive property is true).
Caution
You must call the Close method to close the stream and release the connection. Failure to do so may cause your application to run out of connections.
When using the POST method, you must get the request stream, write the data to be posted, and close the stream. This method blocks waiting for content to post; if there is no time-out set and you do not provide content, the calling thread blocks indefinitely.
Note
Multiple calls to GetResponse return the same response object; the request is not reissued.
Note
Your application cannot mix synchronous and asynchronous methods for a particular request. If you call the GetRequestStream method, you must use the GetResponse method to retrieve the response.
Note
If a WebException is thrown, use the Response and Status properties of the exception to determine the response from the server.
Note
This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in the .NET Framework.
Note
For security reasons, cookies are disabled by default. If you wish to use cookies, use the CookieContainer property to enable cookies.
