I have a list that when the user save it. It then redirect to aspx page. This page has the item ID and I need to use this aspx to start a workflow on that item.

or if possible if I can just call the workflow and start it directly by redirecting to a the url of the workflow page.  thank you

Hi,

I understand that you want to redirect to another page which has the item ID and start a workflow after saving the list item.

Instead of starting the workflow during the page direction, I suggest you to change the start options for this workflow: start workflow automatically when an item is created  or changed. Then when you click the save button, the workflow will start automatically.

You can also use programming method to start a workflow on a list item on the page. We can Start a workflow using c#, more information: http://www.c-sharpcorner.com/UploadFile/anavijai/how-to-start-the-workflow-for-an-item-using-powershell-in-sharepoint-2010/

If you have any questions, please reply me.

Linda Li