Raise Event from outside

Normally raising event is the responsibility side of a class, but in workflow there is a need to raise event from outside. Here is the code that allow client dynamically raise event externally.

class EventRaiser
    {
        static BindingFlags getEventFlags = BindingFlags.Instance | BindingFlags.NonPublic;
        private object _eventObject;
        private MethodInfo _eventInvoker;

Disconnected Update with Entity Framework

In the first demo, we get disconnected entity, make change of it, and get copy of original copy from the database, and apply the changed entity to the original entity by using context.ApplyPropertyChanges method, and save it back to the database.

Reference and EntityKey

When add an entity to your objectContext, if the entity reference an other existing entity, but that entity is not in memory, you need to create a EntityKey like the following.

Naming in Entity Framework

When using the entity framework designer, you create you entity model with a naming convention. For example, a table "Customer" will map to a entity type "Customer" and entity set "CustomerSet" . It is very tempting to change the name of "CustomerSet" to to Customers. But what about Criterion, its plural forms is Criteria, what about Equipment, it is plural forms is also Equipment. I feel that the default naming convention is good enough, because it tells you it is a set and also my configuration is kept to minimum, isn't this the spirit of convention over configuraiton?

How ObjectContext manage entities

Those objects were created by an internal process called object materialization, which takes the returned data and builds the relevant objects for you. Depending on the query, these could be EntityObjects, anonymous types, or DbDataRecords. By default, for any EntityObjects that are materialized, the ObjectContext creates an extra object behind the scenes, called an ObjectStateEntry. It will use these ObjectStateEntry objects to keep track of any changes to their related entities. If you execute an additional query using the same context, more ObjectStateEntry objects will be created for any newly returned entities and the context will manage all of these as well. The context will keep track of its entries as long as it remains in memory. The ObjectContext can track only entities. It cannot keep track of anonymous types or nonentity data that is returned in a DbDataRecord.