由於gridpanel的單元格里的文字太多時候，都由省略號代替，就想實現如題的功能，經過反復實驗，終於搞定了！直接上代碼：
me.on('itemmouseenter', function (view, record, item, index, e, eOpts) {
if (view.tip == null) { //這塊判斷很重要，不能每次都創建個tooltip，要不顯示會有問題。
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]);
});
解釋下：這里截取主要的代碼，實際中，就是監聽你的表格itemmouseenter這個事件就行了！
效果如圖！
