ios - Fix the aspect ratio of the first row in UITableView -

i'm creating screen, imagine facebook profile screen.. tableview , first cell image. goal image maintains aspect ratio, different screen sizes don't have worry sizing it..

i can't work view, if set specific constraints, cell won't set correct height..

i have little project showing constraints, in link..

my vc code:

class viewcontroller: uitableviewcontroller{      override func viewdidload() {         super.viewdidload()         self.tableview.datasource = self         self.tableview.delegate = self         self.tableview.estimatedrowheight = 100         self.tableview.rowheight = uitableviewautomaticdimension          self.tableview.reloaddata()     }      override func tableview(tableview: uitableview, cellforrowatindexpath indexpath: nsindexpath) -> uitableviewcell {         let cell = tableview.dequeuereusablecellwithidentifier("cell", forindexpath: indexpath)         return cell     }      override func tableview(tableview: uitableview, numberofrowsinsection section: int) -> int {         return 1     } } 

my constrains:

if height of table view cell function of table view's width, might easier implement heightforrowatindexpath delegate method return width of table view multiplied ratio want. take constraints out of picture entirely, , more efficient.