C# WIN FORM-SEPARATE DATABASE CONNECTION CLASS TO SQL

I have seen most of people try to connect with database with creating database connection again and again..OOp concept we can use to prevent that problem. Use following class for call any place to connect with data base..


public class dbCon
{
    string strconnection="Data Source=Rajitha-PC\\SQLexpress;Initial Catalog=POS;User ID=etutor_master_admin;Password=123;Integrated Security=True";
 
    SqlConnection sqlcon = new SqlConnection();
    SqlCommand sqlcmd = new SqlCommand();
    SqlDataAdapter da = new SqlDataAdapter();
    DataTable dt = new DataTable();

    public void connect()
    {      
        sqlcon = new SqlConnection(strconnection);
        sqlcon.Open();
    }
    public void disconnect()
    {
        if (sqlcon.State == ConnectionState.Open)
        {
            sqlcon.Close();
            sqlcon.Dispose();
        }
    }
    public DataTable ReadData(string query)
    {
        try
        {
            connect();
            sqlcmd = new SqlCommand(query, sqlcon);
            da = new SqlDataAdapter(sqlcmd);
            dt = new DataTable();
            da.Fill(dt);          
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally
        {
            disconnect();
        }
        return dt;
    }
    public void QryCommand(string query)
    {
        try
        {
            connect();
            sqlcmd = new SqlCommand(query, sqlcon);
            sqlcmd.ExecuteNonQuery();
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally
        {
            disconnect();
        }
    }



 Thats it..

Now Yo can call these from your coding windows

dbCon db = new dbCon();

DataTable dt=new DataTable();

dt = db.ReadData("select * from emp");

DataGridView1.DataSource=dt;