How to Create WF with C#

There are basically two types of workflows we can create in Visual Studio:

1. Sequential Workflow.
2. State Machine Workflow.

Following articles gives you basic idea behind both WF:

Article-1 : Difference Between Sequential Workflow & State machine workflow?
Article-2 :MSDN Blog

Following articles helps you to create sequential workflows in visual studio:

1. https://sergeluca.wordpress.com/2011/01/06/step-by-step-tutorial-creating-workflows-for-sharepoint-2010-step-115/

2. https://babu143.wordpress.com/2012/12/24/creating-a-sequential-workflow-for-sharepoint-2010-using-visual-studio-a-step-by-step-guide/

3. https://msdn.microsoft.com/en-us/library/office/hh824675%28v=office.14%29.aspx

4. http://www.nothingbutsharepoint.com/2012/12/20/sequential-workflow-in-sharepoint-2010-using-visual-studio-2010-aspx-2/

5. http://www.c-sharpcorner.com/blogs/how-to-create-sequential-workflow-in-sharepoint-2010-using-visual-studio-2010

Here is the good example to start with SP workflow using Visual studio.

Please follow the below steps:

1-Start with a Sequential Workflow. Start Visual Studio and create a new project from the template SharePoint --> Sequential Workflow.

2-In the next screen select the option Site Workflow.

3-In the next screen, leave the default option saying the user manually starts the Workflow.

4-Create Activity

What is an Activity?

A Workflow consists of a series of Activities. We can add Activities using the Toolbox. There are different types of Activities like Code Activity, SendEmail, etc.

5-Drag and drop a Code Activity from the toolbox.

6-Add code for the Activity, add code for this Activity. Double click on the codeActivity1

    private void codeActivity1_ExecuteCode(object sender, EventArgs e)
    {
    using (SPWeb web = SPContext.Current.Web)
    {
    SPList list = web.Lists["Manager"];
    foreach (SPListItem item in list.Items)
    {
        if (item["Address"] == null)
        {
            item["Address"] = "PLEASE SET THE ADDRESS!";

            item.Update();
        }
      }
     }
    }

7-Build and Deploy the Solution.