C# 0 The Complete Reference

PART II

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825

Method

Description

public static WebRequest Create(string 

uri

)

Creates a 

WebRequest

 object for the URI 

specified by the string passed by 

uri.

 The object 

returned will implement the protocol specified by 

the prefix of the URI. Thus, the object will be an 

instance of a class that inherits 

WebRequest

. A 

NotSupportedException

 is thrown if the requested 

protocol is not available. A 

UriFormatException

 is 

thrown if the URI format is invalid. 

public static WebRequest Create(Uri 

uri

)

Creates a 

WebRequest

 object for the URI specified 

by

uri.

 The object returned will implement the 

protocol specified by the prefix of the URI. Thus, 

the object will be an instance of a class that 

inherits

WebRequest

. A 

NotSupportedException

 is 

thrown if the requested protocol is not available.

public vir tual Stream GetRequestStream( )

Returns an output stream associated with the 

previously requested URI.

public vir tual WebResponse GetResponse( )

Sends the previously created request and waits 

for a response. When a response is received, it is 

returned as a 

WebReponse

 object. Your program 

will use this object to obtain information from the 

specified URI. 

T

ABLE

 25-1 

The Methods Defi ned by 

WebRequest

 that Suppor t Synchronous Communications

Property

Description

public AuthenticationLevel

    AuthenticationLevel( get; set; }

Obtains or sets the authentication level. 

public vir tual RequestCachePolicy

    CachePolicy { get; set; }

Obtains or sets the cache policy, which controls 

when a response can be obtained from the cache. 

public vir tual string

     ConnectionGroupName { get; set; }

Obtains or sets the connection group name. 

Connection groups are a way of creating a set of 

requests. They are not needed for simple Internet 

transactions.

public vir tual long ContentLength { get; set; }

Obtains or sets the length of the content.

public vir tual string ContentType { get; set; }

Obtains or sets the description of the content.

public vir tual ICredentials

     Credentials { get; set; }

Obtains or sets credentials. 

public static RequestCachePolicy

    DefaultCachePolicy { get; set; }

Obtains or sets the default cache policy, which 

controls when a request can be obtained from the 

cache.

T

ABLE

 25-2 

The Proper ties Defi ned by 

WebRequest

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