iOS

 Solution:      var   viewModel : My Model ? {          didSet  {              bindModel ()         }     } You must have to define the correct model in this.That's why the issue came.If model is wrong the above issue will shown...

 Solution:                  let  tapGestureRecognizer =  UITapGestureRecognizer ( target : vc,  action :  #selector (vc. tapEventAction ( se nder :)))                 cell.i mg . addGestur eRecognizer ( tapGestureRecognizer)                 } When tap called       @objc   func   tapEventAction ( sender :  UITapGestureRecognizer ) {          let  btn = sender. view   as !  UIImageView }

 Problem: While i tried to copy one image from one path to another path.That time i faced the error like below. {Error Domain=NSPOSIXErrorDomain Code=17 "File exists"}}]... Solution: While copy the file you must have to append the filename in the pasted url path and paste it.Then only it will works good.Otherwise the above error will be occur.

 Problem: SwipeCollectionViewCellDelegate not working while using  swipecellkit. Solution: cell.delegate = self You must have the above line then only it will works

Solution:  While setting constraints that not updated then must check the below condition.Layout must be infered not autoresizing.

 Problem: I had used KNContactsPicker for adding contacts in my app.But it fetches empty phone numbers also .How to avoid fetching empty contacts swift? Solution: KNcontact picker had settings.You can also select multiple contacts.You can use the condition as below that  " !contact. phoneNumbers . isEmpty ".For fetching the contacts. Code: import  KNContactsPicker     var   settings  =  KNPickerSettings ()  settings . selectionMode  = . multiple settings . subtitleDisplayInfo  = . phoneNumber settings . conditionToDisplayCon tact  = { contact  in                  return  !contact. phoneNumbers . isEmpty             } let  controller =  KNContactsPicker ( delegate :  self ,  settings :  self . settings ) self . navigationController ?. pre sent (controller,  animated :  true ,  completion :  ...

 Solution: iOS had some specific guidelines for coding. Variable declaration: Variable must start with small letters.If they had second important name then that name have capital letter.Like below var name:String!  // correct var Name:String!  // wrong var firstName:String! //correct  var Firstname:String! //Wrong Function Declaration:    func didChangesFontSize (fontSize: Float ) // correct     func  D idchangesfontsize (fontSize: Float ) // Wrong  Functions must start with small letter and follow to capital letters.