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WebClient.OpenRead Method (String)

Opens a readable stream for the data downloaded from a resource with the URI specified as a String.

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

public Stream OpenRead(
	string address
)

Parameters

address
Type: System.String
The URI specified as a String from which to download data.

Return Value

Type: System.IO.Stream
A Stream used to read data from a resource.

ExceptionCondition
ArgumentNullException

The address parameter is null.

WebException

The URI formed by combining BaseAddress, address is invalid.

-or-

An error occurred while downloading data.

The OpenRead method creates a Stream instance used to read the contents of the resource specified by the address parameter. This method blocks while opening the stream. To continue executing while waiting for the stream, use one of the OpenReadAsync methods.

If the BaseAddress property is not an empty string ("") and address does not contain an absolute URI, address must be a relative URI that is combined with BaseAddress to form the absolute URI of the requested data. If the QueryString property is not null, it is appended to address.

This method uses the RETR command to download an FTP resource. For an HTTP resource, the GET method is used.

NoteNote

You must call Stream.Close when finished with the Stream to avoid running out of system resources.

NoteNote

This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing.

The following code example opens the resource identified by uriString and displays the results on the system console. Note that the Stream returned by OpenRead is closed when the data has been read.


			// Create a new WebClient instance.
			WebClient myWebClient = new WebClient();
			// Download home page data. 
			Console.WriteLine("Accessing {0} ...",  uriString);						
			// Open a stream to point to the data stream coming from the Web resource.
			Stream myStream = myWebClient.OpenRead(uriString);

			Console.WriteLine("\nDisplaying Data :\n");
			StreamReader sr = new StreamReader(myStream);
			Console.WriteLine(sr.ReadToEnd());


			// Close the stream. 
			myStream.Close();


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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

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