title: Expanding/Collapsing All The Master Rows devepress mvc
body: <p>I am using this link <a href="http://demos.devexpress.com/MVCxGridViewDemos/MasterDetail/MasterDetail" rel="nofollow">http://demos.devexpress.com/MVCxGridViewDemos/MasterDetail/MasterDetail</a> to devolp master and details grid. 
  Now I want to expanding/collapsing all the master rows when click on button.</p>