WebRequest.PreAuthenticate Property


The .NET API Reference documentation has a new home. Visit the .NET API Browser on docs.microsoft.com to see the new experience.

When overridden in a descendant class, indicates whether to pre-authenticate the request.

Namespace:   System.Net
Assembly:  System (in System.dll)

public virtual bool PreAuthenticate { get; set; }

Property Value

Type: System.Boolean

true to pre-authenticate; otherwise, false.

Exception Condition

Any attempt is made to get or set the property, when the property is not overridden in a descendant class.

With the exception of the first request, the PreAuthenticate property indicates whether to send authentication information with subsequent requests without waiting to be challenged by the server. When PreAuthenticate is false, the WebRequest waits for an authentication challenge before sending authentication information.


The WebRequest class is an abstract class. The actual behavior of WebRequest instances at run time is determined by the descendant class returned by the WebRequest.Create method. For more information about default values and exceptions, see the documentation for the descendant classes, such as HttpWebRequest and FileWebRequest.

The following example sets the PreAuthenticate property to true so that the NetworkCredential stored in the Credentials property will be sent to along with the resource request.

                  // Create a new webrequest to the mentioned URL.
WebRequest myWebRequest=WebRequest.Create(url);

// Set 'Preauthenticate'  property to true.  Credentials will be sent with the request.

Console.WriteLine("\nPlease enter your credentials for the requested Url");
string UserName=Console.ReadLine();
string Password=Console.ReadLine();

// Create a New 'NetworkCredential' object.
NetworkCredential networkCredential=new NetworkCredential(UserName,Password);

// Associate the 'NetworkCredential' object with the 'WebRequest' object.

// Assign the response object of 'WebRequest' to a 'WebResponse' variable.
WebResponse myWebResponse=myWebRequest.GetResponse();

.NET Framework
Available since 1.1
Return to top