ios - Buttons in iPad not clickable -

i creating buttons using data array. should following:

override func viewdidload()  {         super.viewdidload()           var xmargin:cgfloat = 20.0      var ytopmargin:cgfloat = 40.0        var = 1        let datatanks = ["button 1", "button 2", "button 3", "button 4", "button 5", "button 6"]       index in 0...5      {      let button = uibutton()      button.tag=index      var buttonframe = self.view.frame      buttonframe.origin.x += xmargin      buttonframe.origin.y += ytopmargin      buttonframe.size.width = 200      buttonframe.size.height = 200       button.frame = buttonframe      button.layer.cornerradius = 15.0      button.layer.shadowcolor = uicolor(red: 64/255, green: 64/255, blue: 64/255, alpha: 1).cgcolor      button.layer.shadowopacity = 0.5      button.layer.shadowradius = 5      button.layer.shadowoffset = cgsizemake(2.0, 2.0)      button.layer.zposition = 10       button.backgroundcolor = uicolor.lightgraycolor()      button.enabled=false       if(index==2)      {         button.enabled=true         button.backgroundcolor = uicolor(red: 153/255, green: 0/255, blue: 0/255, alpha: 1.0)      }      if(index==3)      {         button.enabled=true         button.backgroundcolor = uicolor(red: 0/255, green: 0/255, blue: 102/255, alpha: 1.0)      }      button.settitle(datatanks[index], forstate: uicontrolstate.normal)        button.titlelabel!.numberoflines = 3;          button.addtarget(self, action: #selector(mytestviewcontroller.didtouchbutton), forcontrolevents: uicontrolevents.touchupinside)       self.view.addsubview(button)        xmargin+=250.0       i+=1          if(i > 3 )         {             ytopmargin+=300.0             xmargin=20.0              i=1         }      }    }   func didtouchbutton(sender:uibutton!) {          print("button - \(btnsendtag.tag)")     } 

using above code, few buttons clickable others not. not sure what's causing button not work. can help?

this normal because disactivated other buttons except index 2 , 3.

button.enabled=false 

^ 'what's causing button not work'