WorkflowRuntime::CreateWorkflow Method (XmlReader^)

.NET Framework (current version)

Creates a workflow instance by using the specified XmlReader.

Namespace: System.Workflow.Runtime
Assembly: System.Workflow.Runtime (in System.Workflow.Runtime.dll)

Syntax

public:
WorkflowInstance^ CreateWorkflow(
	XmlReader^ workflowDefinitionReader
)

Parameters

workflowDefinitionReader: Type: System.Xml::XmlReader^
An XmlReader that contains the workflow definition.

Return Value

Type: System.Workflow.Runtime::WorkflowInstance^

The created workflow instance.

Exceptions

Exception	Condition
ArgumentNullException	workflowDefinitionReader is a null reference (Nothing in Visual Basic).
ObjectDisposedException	The WorkflowRuntime is disposed.

Remarks

The workflow instance is created from a XAML workflow definition file referenced by the XmlReader.

Before the WorkflowInstance is created, validation is executed on it. If any validation errors occur, the WorkflowValidationFailedException is thrown. This works well for simple scenarios, but in a server environment, revalidating a workflow for every activation might be unnecessary overhead.

For more information about disabling validation, see ValidateOnCreate.

Examples

The following example demonstrates how to create a workflow given a XAML-based workflow definition.

static void Main(string[] args)
{
    using (WorkflowRuntime workflowRuntime = new WorkflowRuntime())
    {
        AutoResetEvent waitHandle = new AutoResetEvent(false);
        workflowRuntime.WorkflowCompleted += delegate(object sender, WorkflowCompletedEventArgs e)
        {
            waitHandle.Set();
        };
        workflowRuntime.WorkflowTerminated += delegate(object sender, WorkflowTerminatedEventArgs e)
        {
            Console.WriteLine(e.Exception.Message);
            waitHandle.Set();
        };

        TypeProvider typeProvider = new TypeProvider(null);
        // Add referenced assemblies, if needed
        // typeProvider.AddAssembly(...);
        workflowRuntime.AddService(typeProvider);

        using (XmlReader reader = XmlReader.Create("Workflow1.xoml"))
        {
            WorkflowInstance instance = workflowRuntime.CreateWorkflow(reader);
            instance.Start();
        }

        waitHandle.WaitOne();
    }
}

Version Information

.NET Framework
Available since 3.0