UnityScript Callback Functions: Cannot cast from source type to destination type.

Unity Engine
1

Is it possible to pass functions as parameters to other script functions in UnityScript? Please note I am not using C# at all.

I’m getting this error:

InvalidCastException: Cannot cast from source type to destination type.
ActorController.FindPathToObject (UnityEngine.GameObject obj, ICallable callback)

When trying to run the code:

_actorCtrl.FindPathToObject(currentTarget, OnPathComplete);

The definition for FindPathToObject:

function FindPathToObject(obj : GameObject, callback: Function){
    // do stuff here
}

The error comes from attempting to pass the callback argument, the gameobject parameter works fine by itself.

Any help would be greatly appreciated

2

It would usually be better to use the function type, rather than Function, since you define the exact types a function can use.

function Start () {
	var x = Foo;
	Bar(x);
}

function Foo (i : int) : String {
	return (i*2).ToString();
}

function Bar (f : function(int):String) {
	var s : String = f(2);
	Debug.Log (s);
}

In this example, the Bar function can only use functions that take an int and return a string. This is basically the same as delegates in C# (and in fact the function type in Unityscript is compatible with delegates in C#).

–Eric