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WebRequest.Create Method (String)

.NET Framework 1.1

Initializes a new WebRequest instance for the specified URI scheme.

[Visual Basic]
Overloads Public Shared Function Create( _
   ByVal requestUriString As String _
) As WebRequest
[C#]
public static WebRequest Create(
 string requestUriString
);
[C++]
public: static WebRequest* Create(
 String* requestUriString
);
[JScript]
public static function Create(
   requestUriString : String
) : WebRequest;

Parameters

requestUriString
The URI that identifies the Internet resource.

Return Value

A WebRequest descendant for the specific URI scheme.

Exceptions

Exception Type Condition
NotSupportedException The request scheme specified in requestUriString has not been registered.
ArgumentNullException requestUriString is a null reference (Nothing in Visual Basic).
SecurityException The caller does not have permission to connect to the requested URI or a URI that the request is redirected to.
UriFormatException The URI specified in requestUriString is not a valid URI.

Remarks

The Create method returns a descendant of the WebRequest class determined at run time as the closest registered match for requestUri.

For example, when a URI beginning with http:// is passed in requestUri, an HttpWebRequest is returned by Create. If a URI beginning with file:// is passed instead, the Create method will return a FileWebRequest instance.

The .NET Framework includes support for the http://, https://, and file:// URI schemes. Custom WebRequest descendants to handle other requests are registered with the RegisterPrefix method.

The Create method uses the requestUriString parameter to create a Uri instance that it passes to the new WebRequest.

Example

[Visual Basic, C#, C++] The following example uses Create to instantiate an HttpWebRequest instance. A string representing the target url is used as the constructor parameter.

[Visual Basic] 

Dim ourUri As New Uri(url)
' Create a 'WebRequest' object with the specified url. 

Dim myWebRequest As WebRequest = WebRequest.Create(url)

' Send the 'WebRequest' and wait for response.
Dim myWebResponse As WebResponse = myWebRequest.GetResponse()

' "ResponseUri" property is used to get the actual Uri from where the response was attained.
If ourUri.Equals(myWebResponse.ResponseUri) Then
    Console.WriteLine(ControlChars.Cr + "Request Url : {0} was not redirected", url)
Else
    Console.WriteLine(ControlChars.Cr + "Request Url : {0} was redirected to {1}", url, myWebResponse.ResponseUri)
End If 

' Release resources of response object.
myWebResponse.Close()


[C#] 
Uri ourUri = new Uri(url);            

// Create a 'WebRequest' object with the specified url. 
WebRequest myWebRequest = WebRequest.Create(url); 

// Send the 'WebRequest' and wait for response.
WebResponse myWebResponse = myWebRequest.GetResponse(); 

// Use "ResponseUri" property to get the actual Uri from where the response was attained.
if (ourUri.Equals(myWebResponse.ResponseUri))
    Console.WriteLine("\nRequest Url : {0} was not redirected",url);   
else
    Console.WriteLine("\nRequest Url : {0} was redirected to {1}",url,myWebResponse.ResponseUri);   
// Release resources of response object.
myWebResponse.Close(); 


[C++] 
Uri* ourUri = new Uri(url);

// Create a 'WebRequest' object with the specified url.
WebRequest* myWebRequest = WebRequest::Create(url);

// Send the 'WebRequest' and wait for response.
WebResponse* myWebResponse = myWebRequest->GetResponse();

// Use "ResponseUri" property to get the actual Uri from where the response was attained.
if (ourUri->Equals(myWebResponse->ResponseUri))
   Console::WriteLine(S"\nRequest Url : {0} was not redirected", url);
else
   Console::WriteLine(S"\nRequest Url : {0} was redirected to {1}", url, myWebResponse->ResponseUri);
// Release resources of response object.
myWebResponse->Close();

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework, Common Language Infrastructure (CLI) Standard

See Also

WebRequest Class | WebRequest Members | System.Net Namespace | WebRequest.Create Overload List | Programming Pluggable Protocols

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