Upload files (low-level method)
The simplest variant of Send() method accepts only the remote file name and a data stream as a parameter. Other variants offer you the way to control, what part of data is uploaded and how it is stored on the remote side, i.e. whether the file is overriden or appended.
To stop the operation without closing connection you can set Cancel parameter of the OnProgress event handler to true. This will stop the upload and close the data channel.