Get a workflow by ID and execute it

get-and-execute-workflow.cs

using System;
using System.Threading;
using System.Threading.Tasks;
using Elsa.Models;
using Elsa.Services;
using Elsa.Services.Models;
using Microsoft.Extensions.DependencyInjection;

namespace Sample
{
    public class RunSomeWorkflow
    {
        private readonly IWorkflowRegistry _workflowRegistry;
        private readonly IServiceProvider _provider;

        public StartWorkflowHandler(IWorkflowRegistry workflowRegistry, IWorkflowInvoker invoker)
        {
            _workflowRegistry = workflowRegistry;
            _invoker = invoker;
        }

        public async Task<WorkflowExecutionContext> RunWorkflowAsync(string workflowId, CancellationToken cancellationToken)
        {
            var workflow = await _workflowRegistry.GetWorkflowDefinitionAsync(workflowId, VersionOptions.Published, cancellationToken);

            if(workflow != null)
            {
                return await _invoker.StartAsync(workflow);
            }

            return null;
        }
    }
}