GridPanel Dynamic add column

var col_updator= Ext.create('Ext.grid.column.Column', {id:"col_Updator",filter:true,items:[{plugins:[{ptype:"clearbutton"}],xtype:"textfield"}],dataIndex:"Updator",text:"更新人"});

App.gc.headerCt.insert(App.gc.columns.length,col_updator);

//App.gc.getView().refresh();