Is there a best way to cast System.Action to UnityAction

Unity Engine
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1

I could only find two way to do this currently, and I don’t know any details about these two implementations.Are they equivalent? Is there any other better way?

    UnityAction ActionToUnityAction(Action source)
    {
        return new UnityAction(source);
    }


    UnityAction ActionToUnityAction2(Action source)
    {
        return () => source();
    }
2

Two different delegates types are just that: two completely different types, and their only common type is System.Delegate. There’s no way to directly cast between them. But you can instance one from another delegate with a matching signature.

3

Too bad that Unity always reinvents their own types instead of using the existing and well known types from the standard

4

I would go with the first option. The second one feels very hacky to me, and introduces bloat to the stack trace:

new UnityAction(action):

Test
UnityEngine.Debug:Log (object)
Test:MyMethod () (at Assets/Test.cs:24)
Test:Start () (at Assets/Test.cs:19)

() => action():

Test
UnityEngine.Debug:Log (object)
Test:MyMethod () (at Assets/Test.cs:24)
DelegateUtility/<>c__DisplayClass1_0:<ActionToUnityAction2>b__0 () (at Assets/DelegateUtility.cs:8)
Test:Start () (at Assets/Test.cs:20)

Another half-decent option is UnityAction unityAction = action.Invoke, which results in a stack trace identical to that of the first option:

action.Invoke:

Test
UnityEngine.Debug:Log (object)
Test:MyMethod () (at Assets/Test.cs:24)
Test:Start () (at Assets/Test.cs:21)