WebClient.UploadString Method (String, String)

Note: This method is new in the .NET Framework version 2.0.

Uploads the specified string to the specified resource, using the POST method.

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

Public Function UploadString ( _
	address As String, _
	data As String _
) As String
Dim instance As WebClient
Dim address As String
Dim data As String
Dim returnValue As String

returnValue = instance.UploadString(address, data)
public String UploadString (
	String address, 
	String data
public function UploadString (
	address : String, 
	data : String
) : String



The URI of the resource to receive the string. For Http resources, this URI must identify a resource that can accept a request sent with the POST method, such as a script or ASP page.


The string to be uploaded.

Return Value

A String containing the response sent by the server.

Exception typeCondition


data is a null reference (Nothing in Visual Basic).


The URI formed by combining BaseAddress and address is invalid.


There was no response from the server hosting the resource.

Before uploading the string, this method converts it to a Byte array using the encoding specified in the Encoding property. This method blocks while the string is transmitted. To send a string and continue executing while waiting for the server's response, use one of the UploadStringAsync 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 STOR command to upload an FTP resource. For an HTTP resource, the POST method is used.


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

The following code example demonstrates calling this method.

Public Shared Sub UploadString(ByVal address As String)

    Dim data As String = "Time = 12:00am temperature = 50"
    Dim client As WebClient = New WebClient()
    '  Optionally specify an encoding for uploading and downloading strings.
    client.Encoding = System.Text.Encoding.UTF8
    '  Upload the data.
    Dim reply As String = client.UploadString(address, data)
    '  Disply the server's response.
End Sub

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

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

.NET Framework

Supported in: 2.0

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