CODEWITHSUNDEEP
c#state-machine
Nestor
Nestor

Reputation: 13990

How to write state machines with c#?

I need to write state machines that run fast in c#. I like the Windows Workflow Foundation library, but it's too slow and over crowded with features (i.e. heavy). I need something faster, ideally with a graphical utility to design the diagrams, and then spit out c# code. Any suggestions? Thanks!

Upvotes: 19

Views: 19105

Answers (2)

Rap
Rap

Reputation: 7292

Yeah, Microsoft may have been ahead of their time with State Machine WF. Sequential Workflows are being received much better.

When we decided on using a state machine, we rolled our own. because we couldn't find an acceptable framework with a UI. Here are our steps. Hope they'll help you.

  1. Create your state interface:

    public interface IApplicationState
{
    void ClickOnAddFindings();        
    void ClickOnViewReport();
    //And so forth
}

  2. Create the states and have them implement the interface:

    public class AddFindingsState : IApplicationState
{
    frmMain _mForm;

    public AddFindingsState(frmMain mForm)
    {
        this._mForm = mForm;
    }

    public void ClickOnAddFindings()
    {            
    }

    public void ClickOnViewReport()
    {
        // Set the State
        _mForm.SetState(_mForm.GetViewTheReportState());
    }
}

  3. Instantiate the states in your main class.

    IApplicationState _addFindingsState;
IApplicationState _viewTheReportState;
_addFindingsState = new AddFindingsState(this);
_viewTheReportState = new ViewTheReportState(this);

  4. When the user does something requiring a change of state, call the methods to set the state:

    _state.ClickOnAFinding();

Of course, the actions will live in the particular instance of the IApplicationState.

Upvotes: 6

bobbymcr
bobbymcr

Reputation: 24177

Ultimately, you probably want the newly redesigned WF engine in .NET 4.0, as it is much faster and provides a flowchart activity (not quite a state machine, but works for most scenarios) and a nice designer UI experience. But since it's not yet released, that is probably not a good answer for now.

As an alternative, you could try stateless, a library specifically for creating state machine programs in .NET. It doesn't appear to provide a UI, but looks well-suited to fulfill your other goals.

Upvotes: 22

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