Does anyone have code or knowledge to share about "how to stop/start a
workflow" in code.

I have a Form Library and a client that wants a webpart to create the
infopath xml file by reading from the parameters upon the incoming URL -
I have done this part, however, they do not want the loaded WorkFlow
to fire when the *.xml file is saved via the webpart. The client wants
to open the document and hit the submit button upon the form. This
submit will save the *.xml back into the form library and then the
workflow will kick off.

So you see within the webpart - I need to stop the workflow, save the
webpart created *.xml to the form library and then restart the workflow
running upon the form library.

Any help?