Refresh ComboBox

Question

I've tried to make the ComboBox refresh itself after I click the delete button, but when I try this it gives me the error:

Items collection cannot be modified when the DataSource property is set.

This is the code from the Delete button:

private void deleteBttn_Click(object sender, EventArgs e)
{
   con.Open();
   string Query = "DROP TABLE [" + comboBox1.SelectedValue.ToString() + "]";
   SqlCommand cmd = new SqlCommand(Query, con);

   SqlDataReader myReader;

   try
   {          
      myReader = cmd.ExecuteReader();
      MessageBox.Show("Deleted");

      this.comboBox1.Items.Remove(this.comboBox1.SelectedItem);
   }
   catch (Exception ex)
   {
      MessageBox.Show(ex.Message);
   }

   con.Close();    
}

And this is the code from the ComboBox:

try
{
   con.Open();

   SqlCommand sqlCmd = new SqlCommand();

   sqlCmd.Connection = con;
   sqlCmd.CommandType = CommandType.Text;
   sqlCmd.CommandText = "Select TABLE_NAME from INFORMATION_SCHEMA.tables";

   SqlDataAdapter sqlDataAdap = new SqlDataAdapter(sqlCmd);        

   DataTable dtRecord = new DataTable();
   sqlDataAdap.Fill(dtRecord);
   comboBox1.DataSource = dtRecord;
   comboBox1.DisplayMember = "table_name";
   comboBox1.ValueMember = "table_name";

   con.Close();
   }
   catch (Exception ex)
   {
      MessageBox.Show(ex.Message);
   } 

Answer 1

Setting the DataSource-Property automatically pairs the ComboBox to the database table and prevents you from manually modifying just the GUI-element.

To force a refresh of the ComboBox (although you might not need to, seeing how the Form should handle it) try this:

comboBox1.DataSource = null;
comboBox1.DataSource = dtRecord;