WebProxy.UseDefaultCredentials Property

Note: This property is new in the .NET Framework version 2.0.

Gets or sets a Boolean value that controls whether the DefaultCredentials are sent with requests.

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

public bool UseDefaultCredentials { get; set; }
/** @property */
public boolean get_UseDefaultCredentials ()

/** @property */
public void set_UseDefaultCredentials (boolean value)

public function get UseDefaultCredentials () : boolean

public function set UseDefaultCredentials (value : boolean)

Property Value

true if the default credentials are used; otherwise, false. The default value is false.

Exception typeCondition


You attempted to set this property when the Credentials property contains credentials other than the default credentials. For more information, see the Remarks section.

Set this property to true when requests made by this WebProxy object should, if requested by the server, be authenticated using the credentials of the currently logged on user. For client applications, this is the desired behavior in most scenarios. For middle tier applications, such as ASP.NET applications, instead of using this property, you would typically set the Credentials property to the credentials of the client on whose behalf the request is made.

The following table shows the effect of setting the UseDefaultCredentials value, based on the value of the Credentials property.

Credentials value

UseDefaultCredentials value




No effect.



Credentials is set to a null reference (Nothing in Visual Basic).

a null reference (Nothing in Visual Basic)


Credentials is set to DefaultCredentials.

Any value other than DefaultCredentials or a null reference (Nothing in Visual Basic)

true or false

Setting UseDefaultCredentials throws an exception.

If UseDefaultCredentials is false, you can change the Credentials property to any credentials. If UseDefaultCredentials is true, changing the Credentials property from DefaultCredentials (the value that is set when the UseDefaultCredentials property is set to true) will throw an exception.

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0