ExtJs4分页

bbar: Ext.create('Ext.PagingToolbar', {            store: store,            displayInfo: true,            displayMsg: 'Displaying topics {0} - {1} of {2}',            emptyMsg: "No topics to display"        }),

var store = Ext.create('Ext.data.JsonStore', {        fields: ['id','gate_level', 'checkpoint_num' , 'project_id','failed_checkpoint_num', 'very_checkpoint_num', 'gate_result' ,'time' ],        proxy: {         type: 'ajax',         url: "qam_gatecheck_ajax.cgi?type=grid&project_id=[% project_id %]",         reader: {             type: 'json',             root: 'result',             totalProperty: 'totalCount'            }}    });