有两个grid，分别有两个store与其对应，目前实现了表格间数据拖拽，就是官方提供的例子，dnd_grid_to_grid.js
现在有个问题，该如何判断第二个grid是否有变化呢？
例如，页面打开后，左边10条 右边5条，左右相互拖拽一条，记录数都不变，但是已经不是原来的记录了。或者从一个grid中拖走一条，再把它拖回来，相当于没变化这都怎么处理啊。
其实就是each一下，然后做下面处理：
Store2.add(record);
Store1.remove(record);
这样是自动commitChanges了么？
用getModifiedRecords得到的总是0
添加和删除record是不会写入modified的,只有编辑的才会。
就你那个例子里面,监听add和remove事件就ok了.
Store
add : ( Store this, Ext.data.Record[] records, Number index )
Fires when Records have been added to the Store
Listeners will be called with the following arguments:
this : Store
records : Ext.data.Record[] The array of Records added
index : Number The index at which the record(s) were added
remove : ( Store this, Ext.data.Record record, Number index )
Fires when a Record has been removed from the Store
Listeners will be called with the following arguments:
this : Store
record : Ext.data.Record The Record that was removed
index : Number The index at which the record was removed
监听store的事件,如datachanged,add,remove,update
监听store的事件,如datachanged,add,remove,update