递归调用Workflow

Question

我有一个工作流，在某个时候，需要递归地触发。

我好像想不出该怎么做。

我尝试了下面的代码，但是上下文最终为null？

private void codeTriggerChildren_ExecuteCode(object sender, EventArgs e)
{
    ActivityExecutionContext context = sender as ActivityExecutionContext;
    //context is null here?!

    IStartWorkflow aWorkflow = context.GetService(typeof(ApprovalFlow)) as IStartWorkflow;

    Dictionary<string, object> parameters = new Dictionary<string, object>();
    parameters.Add("Parm1", "foo");
    parameters.Add("Parm2", "bar");

    Guid guid = aWorkflow.StartWorkflow(typeof(ApprovalFlow), parameters);
}

Answer 1

这里的主要问题是，在本例中，发送方是CodeActivity，而不是ActivityExecutionContext。所以这段代码在第一关就失败了。

下面是一个定制活动的示例，它可以完成您所追求的任务：-

public class RecurseApproval : Activity
{
    protected override ActivityExecutionStatus Execute(ActivityExecutionContext executionContext)
    {
        IStartWorkflow aWorkflow = executionContext.GetService(typeof(IStartWorkflow)) as IStartWorkflow;

        Dictionary<string, object> parameters = new Dictionary<string, object>();
        parameters.Add("Param1", "Foo");
        parameters.Add("Param2", "bar");

        Guid guid = aWorkflow.StartWorkflow(typeof(ApprovalWorkflow), parameters);

        return ActivityExecutionStatus.Closed;

    }
}

请注意，GetService获取IStartWorkflow类型。

Answer 2

您的发件人是CodeActivity类型，而不是ActivityExecutionContext类型。您需要创建一个自定义活动并重写Execute方法，该方法将传递给您一个ActivityExecutionContext。