garden_client/Assets/Script/Extension/ExtensionUnityAction.cs

using UnityEngine;
using UnityEngine.Events;

using System.Collections;

public static class ExtensionUnityAction
{
    public static void SafeInvoke(this UnityAction action)
    {
        if (action != null)
        {
            action.Invoke();
        }
    }

    public static void SafeInvoke<T>(this UnityAction<T> action, T t)
    {
        if (action != null)
        {
            action.Invoke(t);
        }
    }


    public static UnityAction PushEvent(this UnityAction unityAction, UnityAction action)
    {
        return action + unityAction;
    }

    public static UnityAction AddEventOnetime(this UnityAction unityAction, UnityAction action)
    {
        action += () =>
        {
            unityAction -= action;
        };

        return unityAction += action;
    }

    public static UnityAction PushEventOnetime(this UnityAction unityAction, UnityAction action)
    {
        return null;
    }
}