toLua[五] Examples 04_AccessingLuaVariables分析

一.运行工程

本例展示如何用C#访问Lua变量，运行表现很简单，打印几行文本

二.代码分析

2.1代码展示

cs 复制代码

using UnityEngine;
using System.Collections.Generic;
using LuaInterface;

public class AccessingLuaVariables : MonoBehaviour 
{
    private string script =
        @"
            print('Objs2Spawn is: '..Objs2Spawn)
            var2read = 42
            varTable = {1,2,3,4,5}
            varTable.default = 1
            varTable.map = {}
            varTable.map.name = 'map'
            
            meta = {name = 'meta'}
            setmetatable(varTable, meta)
            
            function TestFunc(strs)
                print('get func by variable')
            end
        ";

	void Start () 
    {
#if UNITY_5 || UNITY_2017 || UNITY_2018
        Application.logMessageReceived += ShowTips;
#else
        Application.RegisterLogCallback(ShowTips);
#endif
        new LuaResLoader();
        LuaState lua = new LuaState();
        lua.Start();
        lua["Objs2Spawn"] = 5;
        lua.DoString(script);

        //通过LuaState访问
        Debugger.Log("Read var from lua: {0}", lua["var2read"]);
        Debugger.Log("Read table var from lua: {0}", lua["varTable.default"]);  //LuaState 拆串式table

        LuaFunction func = lua["TestFunc"] as LuaFunction;
        func.Call();
        func.Dispose();

        //cache成LuaTable进行访问
        LuaTable table = lua.GetTable("varTable");
        Debugger.Log("Read varTable from lua, default: {0} name: {1}", table["default"], table["map.name"]);
        table["map.name"] = "new";  //table 字符串只能是key
        Debugger.Log("Modify varTable name: {0}", table["map.name"]);

        table.AddTable("newmap");
        LuaTable table1 = (LuaTable)table["newmap"];
        table1["name"] = "table1";
        Debugger.Log("varTable.newmap name: {0}", table1["name"]);
        table1.Dispose();

        table1 = table.GetMetaTable();

        if (table1 != null)
        {
            Debugger.Log("varTable metatable name: {0}", table1["name"]);
        }

        object[] list = table.ToArray();

        for (int i = 0; i < list.Length; i++)
        {
            Debugger.Log("varTable[{0}], is {1}", i, list[i]);
        }

        table.Dispose();                        
        lua.CheckTop();
        lua.Dispose();
	}

    private void OnApplicationQuit()
    {
#if UNITY_5 || UNITY_2017 || UNITY_2018
        Application.logMessageReceived -= ShowTips;
#else
        Application.RegisterLogCallback(null);
#endif
    }

    string tips = null;

    void ShowTips(string msg, string stackTrace, LogType type)
    {
        tips += msg;
        tips += "\r\n";
    }

    void OnGUI()
    {
        GUI.Label(new Rect(Screen.width / 2 - 300, Screen.height / 2 - 200, 600, 400), tips);
    }
}

2.2 ToLua 部分API用法

下面给出README(LuaFramework\ToLua\Examples\README.md)文档中的解释

* luaState $"Objs2Spawn"$ LuaState通过重载this操作符，访问lua _G表中的变量Objs2Spawn 

* LuaState.GetTable 从lua中获取一个lua table, 可以串式访问比如lua.GetTable("varTable.map.name") 等于 varTable->map->name 

* LuaTable 支持this操作符，但此this不支持串式访问。比如table $"map.name"$ "map.name" 只是一个key，不是table->map->name 

* LuaTable.GetMetaTable() 可以获取当前table的metatable 

* LuaTable.ToArray() 获取数组表中的所有对象存入到object\[\]表中 

* LuaTable.AddTable(name) 在当前的table表中添加一个名字为name的表 

* LuaTable.GetTable(key) 获取t $key$ 值到c#, 类似于 lua_gettable 

* LuaTable.SetTable(key, value) 等价于t $k$ = v的操作, 类似于lua_settable 

* LuaTable.RawGet(key) 获取t $key$ 值到c#, 类似于 lua_rawget 

* LuaTable.RawSet(key, value) 等价于t $k$ = v的操作, 类似于lua_rawset

三.C#访问Lua变量小结

3.1 访问非table变量

Lua 复制代码

num1 = 15

cs 复制代码

Debug.Log(lua["num1"]);

3.2 用key访问table

Lua 复制代码

table1 = {value1 = 2025}

cs 复制代码

Debug.Log(lua["table1.value1"]);

3.3 访问嵌套table

Lua 复制代码

table1 = {table2 = {value2 = 100}}

cs 复制代码

LuaTable table2 = lua.GetTable("table1.table2");
Debug.Log(table2["value2"]);

3.4 遍历数组

Lua 复制代码

table1 = {1,2,3,4,5}

cs 复制代码

    LuaTable table1 = lua.GetTable("table1");
    object[] list = table1.ToArray();
    for (int i = 0; i < list.Length; i++)
    {
        Debugger.Log("table1[{0}], is {1}", i, list[i]);
    }