This documentation is archived and is not being maintained.

WebClient.UploadValues Method (String, String, NameValueCollection)

Uploads the specified name/value collection to the resource identified by the specified URI, using the specified method.

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

Public Function UploadValues ( _
	address As String, _
	method As String, _
	data As NameValueCollection _
) As Byte()


Type: System.String
The URI of the resource to receive the collection.
Type: System.String
The HTTP method used to send the file to the resource. If null, the default is POST for http and STOR for ftp.
Type: System.Collections.Specialized.NameValueCollection
The NameValueCollection to send to the resource.

Return Value

Type: System.Byte()
A Byte array containing the body of the response from the resource.


The address parameter is Nothing.


The data parameter is Nothing.


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


data is Nothing.


An error occurred while opening the stream.


There was no response from the server hosting the resource.


The Content-type header value is not Nothing and is not application/x-www-form-urlencoded.

The UploadValues method sends a NameValueCollection to a resource using the method specified in the method parameter and returns any response from the server. This method blocks while uploading the data. To continue executing while waiting for the server's response, use one of the UploadValuesAsync methods.

If the Content-type header is Nothing, the UploadValues method sets it to application/x-www-form-urlencoded.

If the method parameter specifies a verb that 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.


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

The following code example gathers information from the user (name, age, and address) and posts the values to the server using UploadValues. Any response from the server is displayed on the console.

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

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

' Create a new NameValueCollection instance to hold some custom parameters to be posted to the URL.
Dim myNameValueCollection As New NameValueCollection()

Console.WriteLine("Please enter the following parameters to be posted to the Url")
Dim name As String = Console.ReadLine()

Dim age As String = Console.ReadLine()

Dim address As String = Console.ReadLine()

' Add necessary parameter/value pairs to the name/value container.
myNameValueCollection.Add("Name", name)
myNameValueCollection.Add("Address", address)
myNameValueCollection.Add("Age", age)

Console.WriteLine(ControlChars.Cr + "Uploading to {0} ...", uriString)

' Upload the NameValueCollection.
Dim responseArray As Byte() = myWebClient.UploadValues(uriString, "POST", myNameValueCollection)

' Decode and display the response.
Console.WriteLine(ControlChars.Cr + "Response received was :" + ControlChars.Cr + "{0}", Encoding.ASCII.GetString(responseArray))

.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.