Solving “The ObjectContext instance has been disposed and can no longer be used for operations that require a connection” InvalidOperationException

Question

I am trying to populate a GridView using Entity Frameworkm but every time I am getting the following error:

\"Property accessor \'LoanPro

Answer 1

Most of the other answers point to eager loading, but I found another solution.

In my case I had an EF object InventoryItem with a collection of InvActivity child objects.

class InventoryItem {
...
   // EF code first declaration of a cross table relationship
   public virtual List ItemsActivity { get; set; }

   public GetLatestActivity()
   {
       return ItemActivity?.OrderByDescending(x => x.DateEntered).SingleOrDefault();
   }
...
}

And since I was pulling from the child object collection instead of a context query (with IQueryable), the Include() function was not available to implement eager loading. So instead my solution was to create a context from where I utilized GetLatestActivity() and attach() the returned object:

using (DBContext ctx = new DBContext())
{
    var latestAct = _item.GetLatestActivity();

    // attach the Entity object back to a usable database context
    ctx.InventoryActivity.Attach(latestAct);

    // your code that would make use of the latestAct's lazy loading
    // ie   latestAct.lazyLoadedChild.name = "foo";
}

Thus you aren't stuck with eager loading.