Button listener not working like intended

Hey guys,

Code (csharp):

1.  
2. private void Update()
3.     {
4.         if (player != null)
5.         {
6.             skt = new SkillTree();
7.             skt = skt.GetTree(player.skillTree);
8.             upgrades = skt.GetTreeUpgrades(player.skillTree);
9.         }
10.  
11.         for (int i = 0; i < 8; i++)
12.         {
13.             GameObject holder = GameObject.Find("Holder " + (i + 1));
14.             foreach (Transform go in holder.transform)
15.             {
16.                 switch (go.name)
17.                 {
18.                     case "skillName":
19.                         go.GetComponent<Text>().text = UpgradeNames.getName(i, player.classSelection);
20.                         break;
21.                     case "Button":
22.                         go.GetComponent<Button>().onClick.RemoveAllListeners();
23.                         go.GetComponent<Button>().onClick.AddListener(delegate { upgradeItem(i); });
24.                         break;
25.                     case "upgradeDisplay":
26.                         go.GetComponent<Text>().text = "(" + upgrades[i] + "/4)";
27.                         break;
28.                 }
29.             }
30.         }
31.     }
32.  
33.     public void upgradeItem(int i)
34.     {
35.         Debug.Log("Clicked" + i);
36.         if (player.skillPoints >= 1)
37.         {
38.             if (skt.GetTreeUpgrades(skt.SaveTree(skt))[i - 1] < 4)
39.             {
40.                 skt = skt.GetTree(skt.increaseUpgrade(skt.SaveTree(skt), i - 1));
41.                 player.skillTree = skt.SaveTree(skt);
42.                 player.skillPoints--;
43.             }
44.         }
45.     }
46.  

So I have this small code which is supposed to iterate through each holder and add a listener for the upgradeItem function, but for some reason it always returns 8. For example, I will press the 3rd button (which should return 3) But instead it returns 8, same with all other buttons.
I added a Debug.log at the "button case" for i and it returns the correct numbers. I feel like im doing something stupid anything help is welcomed

 

Code (CSharp):

1. go.GetComponent<Button>().onClick.AddListener(delegate { upgradeItem(i); });

This is where the problem lies. The delegate is referencing i and it is taking the very last value of i which would be 8.

A way around this is to create a local variable that the delegate will reference instead of the changing value of i.

Code (CSharp):

1. int j = i;
2. go.GetComponent<Button>().onClick.AddListener(delegate { upgradeItem(j); });

 

Working perfectly now, Thanks.