CODEWITHSUNDEEP
c#linqlambda
Wonder
Wonder

Reputation: 1020

Lambda expression as an argument to a dynamically dispatched operation

Stuck with error:

Cannot use a lambda expression as an argument to a dynamically dispatched operation without first casting it to a delegate or expression tree type

For a simple example, let's try to get an object from database using entity framework without actually knowing its type:

private DbContext db;
private dynamic test(dynamic entity)
{
    return db.Set(entity.GetType()).First(x => x.Id == entity.Id);
}

How can I make this work?

Upvotes: 0

Views: 10806

Answers (1)

Servy
Servy

Reputation: 203829

Use generics to do this, rather than dynamic:

private DbContext db;
private T test<T>(T entity)
    where T : BaseEntity
{
    return db.Set<T>().First(x => x.Id == entity.Id);
}

Have a BaseEntity that has an Id property, to ensure that the given entity has an Id.

Upvotes: 4

Related Questions