[Bug?] int parameter on dynamically added onClick-Event is wrong

Hey all,

I am making a shop where one can buy weapons. The UI-Buttons to buy the weapons are created dynamically.

If pressed, the button should call the function "BuyWeapon(i)" that gives the player the right weapon from a list, based on the parameter 'i' of the for-loop.

 void Start(){
     for(int i = 0; i < weapons.Count; i++){
         Debug.Log(i);//returns i
         //Instantiate button-prefab
         GameObject go = Instantiate(Resources.Load("Button"),Vector3.zero,container.rotation) as GameObject;
 
         //Add function BuyWeapon() to onClick of current button
         UnityEngine.Events.UnityAction buy = () => { this.BuyWeapon(i); };//passes i as parameter
         go.GetComponent<Button>().onClick.AddListener(buy);
     }
 }

 public void BuyWeapon(int i){
     Debug.Log(i);//returns always weapons.Count, not buttons' index-parameter
     player.itemsList.Add(weapons[i]);
 }

However, if I click any button, I will get an OutOfRange-Error on the function BuyWeapon() because the parameter 'i' on each onClick-event is equals "weapons.Count". But on Start() 'i' will return its value and so it should pass it to the AddFunction-Part.

This is paradox.

Thanks in advance.