WebHeaderCollection.IsRestricted Method (String)
.NET Framework (current version)
Tests whether the specified HTTP header can be set for the request.
Assembly: System (in System.dll)
Parameters
- headerName
-
Type:
System.String
The header to test.
| Exception | Condition |
|---|---|
| ArgumentNullException | headerName is null or Empty. |
| ArgumentException | headerName contains invalid characters. |
The IsRestricted method returns true to indicate that a header is restricted and must be set using properties instead of directly or is set by the system. The restricted headers are:
Accept
Connection
Content-Length
Content-Type
Date
Expect
Host
If-Modified-Since
Range
Referer
Transfer-Encoding
User-Agent
Proxy-Connection
The following example checks the IsRestricted property to see if any headers are prohibited from being set.
try { // Create a web request for "www.msn.com". HttpWebRequest myHttpWebRequest = (HttpWebRequest) WebRequest.Create("http://www.msn.com"); // Get the associated response for the above request. HttpWebResponse myHttpWebResponse = (HttpWebResponse) myHttpWebRequest.GetResponse(); // Get the headers associated with the response. WebHeaderCollection myWebHeaderCollection = myHttpWebResponse.Headers; for (int i = 0; i < myWebHeaderCollection.Count;i++) { // Check if the first response header is restricted. if(WebHeaderCollection.IsRestricted(myWebHeaderCollection.AllKeys[i])) Console.WriteLine("'{0}' is a restricted header", myWebHeaderCollection.AllKeys[i]); else Console.WriteLine("'{0}' is not a restricted header", myWebHeaderCollection.AllKeys[i]); } myHttpWebResponse.Close(); } catch(WebException e) { Console.WriteLine("\nWebException is thrown.\nMessage is:" + e.Message); if(e.Status == WebExceptionStatus.ProtocolError) { Console.WriteLine("Status Code : {0}", ((HttpWebResponse)e.Response).StatusCode); Console.WriteLine("Status Description : {0}", ((HttpWebResponse)e.Response).StatusDescription); Console.WriteLine("Server : {0}", ((HttpWebResponse)e.Response).Server); } } catch(Exception e) { Console.WriteLine("Exception is thrown. Message is :" + e.Message); } }
.NET Framework
Available since 1.1
Available since 1.1
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