I see this a lot in tutorials, with navigation properties as ICollection<T>
.
Is this a mandatory requirement for Entity Framework? Can I use IEnumerable
?
What's the main purpose of using ICollection
instead of IEnumerable
or even List<T>
?
ccode-firstentity-frameworkicollection
I see this a lot in tutorials, with navigation properties as ICollection<T>
.
Is this a mandatory requirement for Entity Framework? Can I use IEnumerable
?
What's the main purpose of using ICollection
instead of IEnumerable
or even List<T>
?
Best Answer
Usually what you choose will depend on which methods you need access to. In general -
IEnumerable<>
(MSDN: http://msdn.microsoft.com/en-us/library/system.collections.ienumerable.aspx) for a list of objects that only needs to be iterated through,ICollection<>
(MSDN: http://msdn.microsoft.com/en-us/library/92t2ye13.aspx) for a list of objects that needs to be iterated through and modified,List<>
for a list of objects that needs to be iterated through, modified, sorted, etc (See here for a full list: http://msdn.microsoft.com/en-us/library/6sh2ey19.aspx).From a more specific standpoint, lazy loading comes in to play with choosing the type. By default, navigation properties in Entity Framework come with change tracking and are proxies. In order for the dynamic proxy to be created as a navigation property, the virtual type must implement
ICollection
.More information on Defining and Managing RelationshipsMSDN