Gets or sets a value that controls whether default credentials are sent with requests by the handler.
Assembly: System.Net.Http (in System.Net.Http.dll)
Set this property to true when requests made by the HttpClientHandler 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.