如何从数据库中填充combobox项，而不是在任何地方复制相同的代码(如何将代码更改为使用OOP)?

SqlDataReader myreader = null;
    SqlConnection sqlConn = null;

     cmbCat.Items.Clear();
    sqlConn = new SqlConnection("Data Source=tin;Initial Catalog=sample;Trusted_Connection=yes;");
    sqlConn.Open();
    SqlCommand sqlComm = new SqlCommand("SELECT members FROM  dbo.tbl_Category", sqlConn);

    myreader = sqlComm.ExecuteReader();
    if (myreader != null)
    {
        while (myreader.Read())
        {

            cmbCat.Items.Add(myreader["members"]);

        }
    }

    {
        if (myreader != null)
            myreader.Close();
        if (sqlConn != null)
        {
            if (sqlConn.State == ConnectionState.Open)
                sqlConn.Close();
        }
    }
SqlDataReader myreader = null;
    SqlConnectio