First i create a gird panel with {store:store1, column:column1} ;
I add ftype: 'search' component to grid panel,
then i use grid.reconfigure(store2,column2) to change the store and column.
after that , i found when i click the search button , ext use the store1 to request,
so my question is how to reconfigure the search component like the xtype: 'pagingtoolbar''s method bindStore(store2)?