ObjectContext disposed also in opened context of EF

Question

I have this method for creating DataTable:

private DataTable toDataTable<T>(IEnumerable<T> items)
    {
        var tb = new DataTable(typeof(T).Name);
        using (var context = new MyEntity())
        {
            PropertyInfo[] props = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);

            foreach (var prop in props)
            {
                tb.Columns.Add(prop.Name, prop.PropertyType);
            }

            foreach (var item in items)
            {
                var values = new object[props.Length];
                for (var i = 0; i < props.Length; i++)
                {
                    values[i] = props[i].GetValue(item, null);
                }

                tb.Rows.Add(values);
            }
        }
       return tb;

    }

but it give me this error in second foreach:

The ObjectContext instance has been disposed and can no longer be used for operations that require a connection.

since I opened my EF's context;why again this error occurs?

Answer 1

The IEnumerable<T> that you are passing into toDataTable<T>() has not been realized yet. The context of items is already disposed. You have forgotten a ToList() in the calling code.