ext 处理后台传过来的json

Question

代码如下：

Ext.Ajax.request({
url:'http://localhost:8080/robot/robotcheck/getTaskList.hs',
method:'post',
success:function(data){
var jsonobj = eval('(' + data.responseText + ')');
alert(data.responseText + "111");
alert(data.rows + "222");
}
});

 data里的内容如下：
     {"rows":[{"startTime":"2016-06-22 14:47:59.0","bdzName":"殿跟变","areaName":"500kV设备区","taskId":784,"dwName":"国网宁波供电公司","robotId":1,"taskName":"殿跟变33例行巡视20160621","robotStatus":1,"dianchi":"220KV/1200KV","sumCounts":1,"hwCounts":0,"gqCounts":1,"alarmCounts":1},{"startTime":"2016-06-22 14:48:28.0","bdzName":"殿跟变","areaName":"500kV设备区","taskId":787,"dwName":"国网宁波供电公司","robotId":1,"taskName":"殿跟变66例行巡视20160621","robotStatus":1,"dianchi":"220KV/1200KV","sumCounts":1,"hwCounts":0,"gqCounts":1,"alarmCounts":1}],"totalCount":7}

    现在我想取rows里的值，我上面alert里的写法都不行,求大神指教,谢谢