Cancel Hanlder

The cancel handler view provides a way to define activity cancellation logic. A cancel handler has some similarities to the fault handlers just discussed. Like fault handlers, they are attached only to a composite activity.However, cancel handlers don’t catch and handle exceptions. Instead, they specify the cleanup actions that take place when an executing activity is canceled.

actions that take place when an executing activity is canceled. The need for cancel handlers is best illustrated with an example: A ListenActivity is a composite activity that allows you to define multiple child activities under it. Assume that each child of the ListenActivity is a HandleExternalEventActivity that listens for a different external event. With this scenario, each HandleExternalEventActivity is executing at the same time waiting for an event. Only one of these children will eventually receive its event and complete execution. The other sibling activities will be canceled by the ListenActivity parent. By entering a cancel handler for the parent ListenActivity, you define the steps to execute when the incomplete children are canceled. You won’t always need a cancel handler. But if your activities require any cleanup when they are canceled, a cancel handler is an appropriate place to define that logic.

ActivityExecutionContext

1. It is a container of services that is availabe to activities ruing their execution. This set of service is the same for all activities in all WF program instances. Some services are provided by the WF runtime and are always obtainable from AEC. Custom services can be offered by the application that hosts the WF runtime; such services are made available to activities by using the AddService method of WorkflowRuntime.

   class ReadLine:Activity
   {
       private string text;
       public string Text
       {
           get { return text; }
       }
   
   

Test asp.net mvc route

//arrange
RouteCollection routes = new RouteCollection();
MvcApplication.RegisterRoutes(routes);
var httpContextMock = new Mock<HttpContextBase>();
httpContextMock.Expect(c => c.Request.AppRelativeCurrentExecutionFilePath).Return("~/product/list");

mvc routing

Routing is actually not part of the asp.net mvc component. But mvc depends on this asp.net components. To add a route to the route table, you can use the following code.

EF JOIN

Zlatko Michailov, the Entity SQL program manager at Microsoft, writes in his blog: "A well defined query against a well defined entity data model does not need JOIN. Navigation properties in combination with nesting sub-queries should be used instead. These latter constructs represent task requirements much more closely than JOIN does."—http://blogs.msdn.com/esql/ (November 1, 2007). To show it means, here is an example.