Accessing class instance in swift

Question

I've got a Graph class which is an UIView and I'm initializing it inside mainVC.swift:

class MainVC : UIViewController{
   let graph : Graph!

   override func viewDidLoad(){
      super.viewDidLoad()
      let data_x : [Double] = [...]
      let data_y : [Double] = [...]
      ...
      graph = Graph(frame: CGRect(...), color: ..., xData: data_x, yData: data_y, darkMode: ...)
      view.addSubview(graph)
      ...
      }

Now I would like to access function inside instance of the class which I've created in MainVC in different class (to populate data in TableView).

var g : Graph = MainVC.graph returns "Instance member graph cannot be used on type MainVC" I've also tried using static variable but there was an error.

score 1 · Accepted Answer · answered Jun 29 '17 at 12:49

This is one of the way which i known check it out.

class MainVC {
   let graph : Graph! 
}

graph is a stored property is a constant or variable that is stored as part of an instance of a particular class.So you tried for accessing instance property not an instance of class.

In your class MainVC make variable as static which holds instance

 static var graph: Graph?

Then store instance of Graph in graph property in Graph class

  MainVc.graph = self

Now you can use in another class where you access graph instance like

  MainVc.graph

@codddeer123 glad to help if it's useful then you can accept answer. — Dharma, Jun 29 '17 at 13:04

score 0 · Answer 2 · answered Jun 29 '17 at 11:50

0

You are accessing an instance variable on a class, not an instance of it.

answered Jun 29 '17 at 11:50

vikingosegundo

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so this variable doesn't hold a reference to the instance of this class? How should I do it then? – mikro098 Jun 29 '17 at 12:18

score 0 · Answer 3 · edited Jun 29 '17 at 13:26

0

let mainVc = MainVC()
let graph = self.graph

edited Jun 29 '17 at 13:26

Simon H

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answered Jun 29 '17 at 11:59

RinaLiu

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then try graph = self.graph, – RinaLiu Jun 29 '17 at 12:23

Accessing class instance in swift

3 Answers3