public void callback(glp_tree tree) { glp_prob prob; if (GLPK.glp_ios_reason(tree) == GLPK.GLP_IROWGEN) { prob = GLPK.glp_ios_get_prob(tree); if (forceError) { GLPK.glp_cli_set_msg_lvl(GLPK.GLP_CLI_MSG_LVL_ALL); try { GLPK.glp_add_rows(prob, -1); } catch (GlpkException ex) { Console.WriteLine("Error in callback: " + ex.Message); } GLPK.glp_cli_set_msg_lvl(GLPK.GLP_CLI_MSG_LVL_OFF); } } }