WebClient.UploadValuesTaskAsync Method (Uri, String, NameValueCollection)
Uploads the specified name/value collection to the resource identified by the specified URI as an asynchronous operation using a task object.
Assembly: System (in System.dll)
[<ComVisibleAttribute(false)>] [<HostProtectionAttribute(SecurityAction.LinkDemand, ExternalThreading = true)>] member UploadValuesTaskAsync : address:Uri * method:string * data:NameValueCollection -> Task<byte>
The URI of the resource to receive the collection.
The HTTP method used to send the collection to the resource. If null, the default is POST for http and STOR for ftp.
The NameValueCollection to send to the resource.
The address parameter is null.
The data parameter is null.
The URI formed by combining BaseAddress, and address is invalid.
method cannot be used to send content.
There was no response from the server hosting the resource.
An error occurred while opening the stream.
The Content-type header is not null or "application/x-www-form-urlencoded".
This operation will not block. The returned Task<'TResult> object will complete after the name/value collection has been uploaded to the resource. The name/value collection is sent asynchronously using thread resources that are automatically allocated from the thread pool.
Asynchronous operations that have not completed can be canceled using the CancelAsync method.
If the underlying request 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 Content-type header is null, this method sets it to "application/x-www-form-urlencoded".
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 in the .NET Framework.
Available since 4.5