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

Try this

comboBox1.Items.Insert(index, dr.GetString(1) + dr.GetString(2));

Where index is an integer value where you want to insert in combobox

Did you mean this

comboBox1.Items.Insert(dr.GetInt32(0), dr.GetString(1) + dr.GetString(2));

If you want to just add in combobox try the following

comboBox1.Items.Add(dr.GetString(1) + dr.GetString(2));

I think you're looking for DataSource

void comboboxrefresh()
{
    cnn.Open();
    SqlCommand cmd = new SqlCommand("SELECT EmployeeID, (EmployeeFirstName + EmployeeLastName) as EmployeeName FROM Employees", cnn);
    DataTable table = new Datatable();
    SqlDataAdapter adapter = new SqlDataAdapter(cmd);
    adapter.Fill(table);

    comboBox1.DisplayMember = "EmployeeName";
    comboBox1.ValueMember = "EmployeeID";

    comboBox1.DataSource = table;

    cnn.Close();
}