由于gridpanel的单元格里的文字太多时候，都由省略号代替，就想实现如题的功能，经过反复实验，终于搞定了！直接上代码：

 

me.on('itemmouseenter', function (view, record, item, index, e, eOpts) {            if (view.tip == null) {  //这块判断很重要，不能每次都创建个tooltip，要不显示会有问题。                view.tip = Ext.create('Ext.tip.ToolTip', {                    // The overall target element.                    target: view.el,                    // Each grid row causes its own separate show and hide.                    delegate: view.itemSelector,                    // Moving within the row should not hide the tip.                    //  trackMouse: false,                    // Render immediately so that tip.body can be referenced prior to the first show.                    renderTo: Ext.getBody()                });            };            var gridColums = view.getGridColumns();            var column = gridColums[e.getTarget(view.cellSelector).cellIndex];             view.el.clean();             view.tip.update(record.data[column.dataIndex]);                                                               });

解释下：这里截取主要的代码，实际中，就是监听你的表格itemmouseenter这个事件就行了！ 效果如图！