ExtJS实现grid表格行提示数据信息代码片段！

listeners: {            render: function(g){                    var view = g.getView();                   var store = g.getStore();               var rowTip = new Ext.ToolTip({                    target: view.mainBody,                       delegate: '.x-grid3-row',                    trackMouse: true,                         renderTo: document.body,                    listeners: {                        beforeshow: function updateTipBody(tip){                            var rowIndex = view.findRowIndex(tip.triggerElement);                            var record = store.getAt(rowIndex);                            tip.body.dom.innerHTML = record.data.measure;                        }                    }                });            }        }