Inserting text gives objectcollection error

Question

I want to insert each row in SQL into combobox, where EmployeeID will be combobox Value, and EmployeeFirstName EmployeeLastName will be text of combobox item. However this line<

Answer 1

First, use Add to add items to the ComboBox. Second, I prefer anonymous type to fill the ComboBox while you use plain native Sql and simple DataReader immediately inside your form.

void comboboxrefresh()
    {
        cnn.Open();
        SqlCommand cmd = new SqlCommand("SELECT EmployeeID,EmployeeFirstName,EmployeeLastName FROM Employees", cnn);
        SqlDataReader dr = cmd.ExecuteReader();
        if (dr.HasRows)
        {
            combobox1.ValueMember = "Id";
            combobox1.DisplayMember = "FullName";

            while (dr.Read())
            {
                comboBox1.Items.Add(
                  new {
                         FullName = dr.GetString(1) + " " + dr.GetString(2), 
                         Id = dr.GetInt32(0)
                      });
            }
        }

        cnn.Close();
    }

Update:

I noticed that naively adding to the Item list is not working! Instead, DataSource property of ComboBox should be set to desired list. So the working code is as:

var list = new List