lua中的update函数驱动方式

写在一个Main里面，然后在C#中使用：

private Action<float,float> luaUpadte;
luaUpadte = luaEnv.Global.Get<Action<float,float>>("update");

main.lua.txt中：

function update(deltaTime, unscaledDeltaTime)
   ……
end

xlua中官方例子中update的驱动方式：

void Awake()
        {
            scriptEnv = luaEnv.NewTable();

            // 为每个脚本设置一个独立的环境，可一定程度上防止脚本间全局变量、函数冲突
            LuaTable meta = luaEnv.NewTable();
            meta.Set("__index", luaEnv.Global);
            scriptEnv.SetMetaTable(meta);
            meta.Dispose();

            scriptEnv.Set("self", this);
            foreach (var injection in injections)
            {
                scriptEnv.Set(injection.name, injection.value);
            }

            luaEnv.DoString(luaScript.text, "LuaTestScript", scriptEnv);

            Action luaAwake = scriptEnv.Get<Action>("awake");
            scriptEnv.Get("start", out luaStart);
            scriptEnv.Get("update", out luaUpdate);
            scriptEnv.Get("ondestroy", out luaOnDestroy);

            if (luaAwake != null)
            {
                luaAwake();
            }
        }

我们可以新创建C#中的LuaTable。
比如上面的Awake方法中，创建了两个LuaTable，分别是：scriptEnv和meta
其中将meta的__index方法，设置为luaEnv.Global
这样scriptEnv的父类就是Global了。

此外，我们还可在scriptEnv注册一些key的value形式的键值对。
使用的方法是Set(key,value)的方式。
比如开始新建的scriptEnv为一个空的table，我们为期注册了元表，注册了self, __index，以及一个gameObject。

我们还可以在C#短获取lua的某个方法，使用Get方法。

这样，就实现了双向访问。C#中负责向lua中输入一些参数，也可以从lua中获取一些方法。

/*
 * Tencent is pleased to support the open source community by making xLua available.
 * Copyright (C) 2016 THL A29 Limited, a Tencent company. All rights reserved.
 * Licensed under the MIT License (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
 * http://opensource.org/licenses/MIT
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
*/

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using XLua;
using System;

namespace XLuaTest
{
    [System.Serializable]
    public class Injection
    {
        public string name;
        public GameObject value;
    }

    [LuaCallCSharp]
    public class LuaBehaviour : MonoBehaviour
    {
        public TextAsset luaScript;
        public Injection[] injections;

        internal static LuaEnv luaEnv = new LuaEnv(); //all lua behaviour shared one luaenv only!
        internal static float lastGCTime = 0;
        internal const float GCInterval = 1;//1 second 

        private Action luaStart;
        private Action luaUpdate;
        private Action luaOnDestroy;

        private LuaTable scriptEnv;

        void Awake()
        {
            scriptEnv = luaEnv.NewTable();

            // 为每个脚本设置一个独立的环境，可一定程度上防止脚本间全局变量、函数冲突
            LuaTable meta = luaEnv.NewTable();
            meta.Set("__index", luaEnv.Global);
            scriptEnv.SetMetaTable(meta);
            meta.Dispose();

            scriptEnv.Set("self", this);
            foreach (var injection in injections)
            {
                scriptEnv.Set(injection.name, injection.value);
            }

            luaEnv.DoString(luaScript.text, "LuaTestScript", scriptEnv);

            Action luaAwake = scriptEnv.Get<Action>("awake");
            scriptEnv.Get("start", out luaStart);
            scriptEnv.Get("update", out luaUpdate);
            scriptEnv.Get("ondestroy", out luaOnDestroy);

            if (luaAwake != null)
            {
                luaAwake();
            }
        }

        // Use this for initialization
        void Start()
        {
            if (luaStart != null)
            {
                luaStart();
            }
        }

        // Update is called once per frame
        void Update()
        {
            if (luaUpdate != null)
            {
                luaUpdate();
            }
            if (Time.time - LuaBehaviour.lastGCTime > GCInterval)
            {
                luaEnv.Tick();
                LuaBehaviour.lastGCTime = Time.time;
            }
        }

        void OnDestroy()
        {
            if (luaOnDestroy != null)
            {
                luaOnDestroy();
            }
            luaOnDestroy = null;
            luaUpdate = null;
            luaStart = null;
            scriptEnv.Dispose();
            injections = null;
        }
    }
}

lua脚本

-- Tencent is pleased to support the open source community by making xLua available.
-- Copyright (C) 2016 THL A29 Limited, a Tencent company. All rights reserved.
-- Licensed under the MIT License (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
-- http://opensource.org/licenses/MIT
-- Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

local speed = 10
local lightCpnt = nil

function start()
	print("lua start...")
	print("injected object", lightObject) --这个lightObject:GetComponent由C#注册进来上面的injections
	lightCpnt= lightObject:GetComponent(typeof(CS.UnityEngine.Light))
end

function update()
	local r = CS.UnityEngine.Vector3.up * CS.UnityEngine.Time.deltaTime * speed
	self.transform:Rotate(r)
	lightCpnt.color = CS.UnityEngine.Color(CS.UnityEngine.Mathf.Sin(CS.UnityEngine.Time.time) / 2 + 0.5, 0, 0, 1)
end

function ondestroy()
    print("lua destroy")
end