WebClient.DownloadData Method (String) (System.Net)

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.NET Framework Class Library
WebClient.DownloadData Method (String)

Downloads the resource with the specified URI as a Byte array.

Namespace:  System.Net
Assembly:  System (in System.dll)
Syntax
Visual Basic
Public Function DownloadData ( _
	address As String _
) As Byte()
C#
public byte[] DownloadData(
	string address
)
Visual C++
public:
array<unsigned char>^ DownloadData(
	String^ address
)
F#
member DownloadData : 
        address:string -> byte[]

Parameters

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

Return Value

Type: System.Byte[]
A Byte array containing the downloaded resource.
Exceptions
Exception Condition
ArgumentNullException

The address parameter is null.

WebException

The URI formed by combining BaseAddress and address is invalid.

-or-

An error occurred while downloading data.

NotSupportedException

The method has been called simultaneously on multiple threads.
Remarks

The DownloadData method downloads the resource with the URI specified by the address parameter. This method blocks while downloading the resource. To download a resource and continue executing while waiting for the server's response, use one of the DownloadDataAsync 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 an empty string, 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.

Note Note

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

The following code example requests data from a server and displays the data returned. It assumes that remoteUri contains a valid URI for the requested data.

Visual Basic


Console.Write(ControlChars.Cr + "Please enter a Url(for example, http://www.msn.com): ")
Dim remoteUrl As String = Console.ReadLine()
' Create a new WebClient instance.
Dim myWebClient As New WebClient()
' Download the home page data.
Console.WriteLine(("Downloading " + remoteUrl))
' DownloadData() method takes a 'uriRemote.ToString()' and downloads the Web resource and saves it into a data buffer.
Dim myDatabuffer As Byte() = myWebClient.DownloadData(remoteUrl)

' Display the downloaded data.
Dim download As String = Encoding.ASCII.GetString(myDataBuffer)
Console.WriteLine(download)

Console.WriteLine("Download successful.")
C#

Console.Write("\nPlease enter a URI (for example, http://www.contoso.com): ");
string remoteUri = Console.ReadLine();

// Create a new WebClient instance.
WebClient myWebClient = new WebClient();
// Download home page data.
Console.WriteLine("Downloading " + remoteUri);                        
// Download the Web resource and save it into a data buffer.
byte[] myDataBuffer = myWebClient.DownloadData (remoteUri);

// Display the downloaded data.
string download = Encoding.ASCII.GetString(myDataBuffer);
Console.WriteLine(download);

Console.WriteLine("Download successful.");
Visual C++

Console::Write( "\nPlease enter a URI (e.g. http://www.contoso.com): " );
String^ remoteUri = Console::ReadLine();

// Create a new WebClient instance.
WebClient^ myWebClient = gcnew WebClient;
// Download home page data.
Console::WriteLine( "Downloading {0}", remoteUri );
// Download the Web resource and save it into a data buffer.
array<Byte>^ myDataBuffer = myWebClient->DownloadData( remoteUri );

// Display the downloaded data.
String^ download = Encoding::ASCII->GetString( myDataBuffer );
Console::WriteLine( download );

Console::WriteLine( "Download successful." );
Version Information

.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
Platforms

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.
See Also

Reference

WebClient Class
DownloadData Overload
System.Net Namespace
Community Content

R. Ian Lee
More trailing periods...
I just ran across the same problem as MadManMarkAu.  Upon further testing it appears that it strips out all trailing periods from not only file names but also directory names.  So, $0$0 $0 $0http://www.microsoft.com/static/managed/img/U.S./cb.gif $0 $0$0 $0 $0gets transmitted as $0$0 $0 $0GET http://www.microsoft.com/static/managed/img/U.S/cb.gif$0 $0 $0$0 $0 $0This is a definite bug in WebClient.$0

MadManMarkAu
This method removes trailing dots
This method, when used to download a file, assumes the web server you are downloading from is running on a Windows platform. Thus, if I download the file "www.example.org/file." it will request "www.example.com/file" without the trailing dot.

The file name "file." in windows will produce a file without an extension, the same as "file". However, on Linux platforms, "file." is a perfectly valid file name, and will be stored as such.