WebClient.UploadFile Method (String, String) (System.Net)

UploadFile Method (String, String)

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Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

.NET Framework Class Library

WebClient..::.UploadFile Method (String, String)

Updated: November 2007

Uploads the specified local file to a resource with the specified URI.

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

Syntax

Visual Basic (Declaration)

Public Function UploadFile ( _
    address As String, _
    fileName As String _
) As Byte()

Visual Basic (Usage)

Dim instance As WebClient
Dim address As String
Dim fileName As String
Dim returnValue As Byte()

returnValue = instance.UploadFile(address, _
    fileName)

public byte[] UploadFile(
    string address,
    string fileName
)

Visual C++

public:
array<unsigned char>^ UploadFile(
    String^ address, 
    String^ fileName
)

public byte[] UploadFile(
    String address,
    String fileName
)

JScript

public function UploadFile(
    address : String, 
    fileName : String
) : byte[]

Parameters

address: Type: System..::.String
The URI of the resource to receive the file. For example, ftp://localhost/samplefile.txt.

fileName: Type: System..::.String
The file to send to the resource. For example, "samplefile.txt".

Return Value

Type: array<System..::.Byte>[]()[]

A Byte array containing the body of the response from the resource.

Exceptions

Exception	Condition
WebException	The URI formed by combining BaseAddress, and address is invalid. -or- fileName is nullNothingnullptra null reference (Nothing in Visual Basic), is Empty, contains invalid characters, or does not exist. -or- An error occurred while uploading the file. -or- There was no response from the server hosting the resource. -or- The Content-type header begins with multipart.

Exception

Condition

WebException

The URI formed by combining BaseAddress, and address is invalid.

-or-

fileName is nullNothingnullptra null reference (Nothing in Visual Basic), is Empty, contains invalid characters, or does not exist.

-or-

An error occurred while uploading the file.

-or-

There was no response from the server hosting the resource.

-or-

The Content-type header begins with multipart.

Remarks

The UploadFile method sends a local file to a resource. This method uses the STOR command to upload an FTP resource. For an HTTP resource, the POST method is used.

This method blocks while uploading the file. To continue executing while waiting for the server's response, use one of the UploadFileAsync methods.

The POST method is defined by HTTP. If the underlying request does not use HTTP and POST is not understood by the server, the underlying protocol classes determine what occurs. Typically, a WebException is thrown with the Status property set to indicate the error.

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.

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 uploads the specified file to the specified URI using UploadFile. Any response returned by the server is displayed on the console.

Visual Basic

Console.Write(ControlChars.Cr + "Please enter the URI to post data to : ")
Dim uriString As String = Console.ReadLine()

' Create a new WebClient instance.
Dim myWebClient As New WebClient()

Console.WriteLine(ControlChars.Cr & _
    "Please enter the fully qualified path of the file to be uploaded to the URI")

Dim fileName As String = Console.ReadLine()
Console.WriteLine("Uploading {0} to {1} ...", fileName, uriString)

' Upload the file to the URI.
' The 'UploadFile(uriString,fileName)' method implicitly uses HTTP POST method. 
Dim responseArray As Byte() = myWebClient.UploadFile(uriString, fileName)

' Decode and display the response.
Console.WriteLine(ControlChars.Cr & "Response Received.The contents of the file uploaded are: " & _
    ControlChars.Cr & "{0}", System.Text.Encoding.ASCII.GetString(responseArray))

Console.Write("\nPlease enter the URI to post data to : ");
String uriString = Console.ReadLine();

// Create a new WebClient instance.
WebClient myWebClient = new WebClient();

Console.WriteLine("\nPlease enter the fully qualified path of the file to be uploaded to the URI");
string fileName = Console.ReadLine();
Console.WriteLine("Uploading {0} to {1} ...",fileName,uriString);

// Upload the file to the URI.
// The 'UploadFile(uriString,fileName)' method implicitly uses HTTP POST method.
byte[] responseArray = myWebClient.UploadFile(uriString,fileName);

// Decode and display the response.
Console.WriteLine("\nResponse Received.The contents of the file uploaded are:\n{0}", 
    System.Text.Encoding.ASCII.GetString(responseArray));

Visual C++

Console::Write( "\nPlease enter the URI to post data to : " );
String^ uriString = Console::ReadLine();

// Create a new WebClient instance.
WebClient^ myWebClient = gcnew WebClient;
Console::WriteLine( "\nPlease enter the fully qualified path of the file to be uploaded to the URI" );
String^ fileName = Console::ReadLine();
Console::WriteLine( "Uploading {0} to {1} ...", fileName, uriString );

// Upload the file to the URI.
// The 'UploadFile(uriString, fileName)' method implicitly uses HTTP POST method.
array<Byte>^responseArray = myWebClient->UploadFile( uriString, fileName );

// Decode and display the response.
Console::WriteLine( "\nResponse Received::The contents of the file uploaded are: \n {0}", 
    System::Text::Encoding::ASCII->GetString( responseArray ) );

Console.Write("\nPlease enter the URI to post data to : ");
String uriString = Console.ReadLine();
// Create a new WebClient instance.
WebClient myWebClient = new WebClient();

Console.WriteLine("\nPlease enter the fully qualified path of the"  
    + " file to be uploaded to the URI");
String fileName = Console.ReadLine();
Console.WriteLine("Uploading {0} to {1} ...", fileName, uriString);
// Upload the file to the URI.
// The 'UploadFile(uriString,fileName)' method implicitly uses
// HTTP POST method.
ubyte responseArray[] = myWebClient.UploadFile(uriString, fileName);
// Decode and display the response.
Console.WriteLine("\nResponse Received.The contents of the file" 
    + " uploaded are: \n{0}", Encoding.get_ASCII().GetString(
    responseArray));

The following code example shows an ASP.NET page that can accept posted files and is suitable for use with the UploadFile method. The page must reside on a Web server. Its address provides the value for the address parameter of the UploadFile method.

Visual Basic

<%@ Import Namespace="System"%>
<%@ Import Namespace="System.IO"%>
<%@ Import Namespace="System.Net"%>
<%@ Import NameSpace="System.Web"%>

<Script language="VB" runat=server>
    Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)

        Dim f As String
        Dim file
        For Each f In Request.Files.AllKeys
            file = Request.Files(f)
            file.SaveAs("c:\inetpub\test\UploadedFiles\" & file.FileName)
        Next f

    End Sub

</Script>
<html>
<body>
<p> Upload complete. </p>
</body>
</html>

<%@ Import Namespace="System"%>
<%@ Import Namespace="System.IO"%>
<%@ Import Namespace="System.Net"%>
<%@ Import NameSpace="System.Web"%>

<Script language="C#" runat=server>
void Page_Load(object sender, EventArgs e) {
    
    foreach(string f in Request.Files.AllKeys) {
        HttpPostedFile file = Request.Files[f];
        file.SaveAs("c:\\inetpub\\test\\UploadedFiles\\" + file.FileName);
    }    
}

</Script>
<html>
<body>
<p> Upload complete.  </p>
</body>
</html>

Permissions

FileIOPermission
to access the local file. Associated enumeration: Read.

Platforms

Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

Version Information