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俺老孙终于可以将指针传递给lua了！

• 希望把指针传给lua
• 但是lua拿到了它
• 还要通过这个指针去访问他指向的东西
• 那咋办

• 首先，是用lua_pushlightuserdata(L,&a);将指针传给lua

• 老子不想说了哈哈

g++ -I /home/ztz123/Desktop/lua-5.4.0/src -L /home/ztz123/Desktop/lua-5.4.0/src A.cpp -llua -ldl

#include 
   
    extern "C" {
   #include "lua.h"#include "lualib.h"#include "lauxlib.h"}typedef struct haha{
   int a;int b;}haha;/* 指向lua解释器的指针 */lua_State* L;static int average(lua_State *L){
   	haha *a = (haha *)lua_topointer(L,-1);	printf("%d\n",a->a);    return 0;}int main ( int argc, char *argv[] ){
       /* 初始化Lua */    L = luaL_newstate();    /* 载入Lua基本库 */    luaL_openlibs(L);    /* 注册自定义函数 */    lua_register(L, "average", average);        luaL_loadfile(L,"avg.lua");    haha a={
   23,89};lua_pcall(L,0,0,0); //居然特么的还必须要有这句话！！     lua_getglobal(L, "func1");    lua_pushlightuserdata(L,&a);    lua_pcall(L, 1, 0, 0);      /* 执行avg.lua文件 */    luaL_dofile(L, "avg.lua");    /* 关闭Lua */    lua_close(L);    /* 暂停 */    printf( "Press enter to exit..." );    getchar();    return 0;}
   

• avg.lua长这样子

function func1(a)print("esfs")average(a)end

如果有两个参数怎么bane？

• 你必须记住最右边的参数是-1
• 往左依次是-2，-3

还有就是我发现lua_topointer(L,-2);

#include 
   
    extern "C" {
   #include "lua.h"#include "lualib.h"#include "lauxlib.h"}typedef struct haha{
   int a;int b;}haha;/* 指向lua解释器的指针 */lua_State* L;static int average(lua_State *L){
   		haha *a = (haha *)lua_topointer(L,-2);	int aa = lua_tonumber(L,-1);	printf("%d\n",a->a);	printf("%d\n",aa);    return 0;}int main ( int argc, char *argv[] ){
       /* 初始化Lua */    L = luaL_newstate();    /* 载入Lua基本库 */    luaL_openlibs(L);    /* 注册自定义函数 */    lua_register(L, "average", average);        luaL_loadfile(L,"avg.lua");    haha a={
   23,89};lua_pcall(L,0,0,0);      lua_getglobal(L, "func1");    lua_pushlightuserdata(L,&a);        lua_pcall(L, 1, 0, 0);      /* 执行avg.lua文件 */    luaL_dofile(L, "avg.lua");    /* 关闭Lua */    lua_close(L);    /* 暂停 */    printf( "Press enter to exit..." );    getchar();    return 0;}
   

function func1(a)print("esfs")average(a,12)end

自己传参给lua的时候要记得从左到右传参啊

#include 
   
    extern "C" {
   #include "lua.h"#include "lualib.h"#include "lauxlib.h"}typedef struct haha{
   int a;int b;}haha;/* 指向lua解释器的指针 */lua_State* L;static int average(lua_State *L){
   	haha *a = (haha *)lua_topointer(L,-2);	int aa = lua_tonumber(L,-1);	printf("%d\n",a->a);	printf("%d\n",aa);    return 0;}int main ( int argc, char *argv[] ){
       /* 初始化Lua */    L = luaL_newstate();    /* 载入Lua基本库 */    luaL_openlibs(L);    /* 注册自定义函数 */    lua_register(L, "average", average);        luaL_loadfile(L,"avg.lua");    haha a={
   23,89};lua_pcall(L,0,0,0);      lua_getglobal(L, "func1");    lua_pushlightuserdata(L,&a);    lua_pushnumber(L,88);        lua_pcall(L, 2, 0, 0);      /* 执行avg.lua文件 */    luaL_dofile(L, "avg.lua");    /* 关闭Lua */    lua_close(L);    /* 暂停 */    printf( "Press enter to exit..." );    getchar();    return 0;}
   

function func1(a,b)print("esfs")average(a,b)end

double数也用pushnumber传递啊

#include 
   
    extern "C" {
   #include "lua.h"#include "lualib.h"#include "lauxlib.h"}typedef struct haha{
   int a;int b;}haha;/* 指向lua解释器的指针 */lua_State* L;static int average(lua_State *L){
   	haha *a = (haha *)lua_topointer(L,-2);	double aa = lua_tonumber(L,-1);	printf("%d\n",a->a);	printf("%9f\n",aa);    return 0;}int main ( int argc, char *argv[] ){
       /* 初始化Lua */    L = luaL_newstate();    /* 载入Lua基本库 */    luaL_openlibs(L);    /* 注册自定义函数 */    lua_register(L, "average", average);        luaL_loadfile(L,"avg.lua");    haha a={
   23,89};lua_pcall(L,0,0,0);      lua_getglobal(L, "func1");    lua_pushlightuserdata(L,&a);    lua_pushnumber(L,34.567999);        lua_pcall(L, 2, 0, 0);      /* 执行avg.lua文件 */    luaL_dofile(L, "avg.lua");    /* 关闭Lua */    lua_close(L);    /* 暂停 */    printf( "Press enter to exit..." );    getchar();    return 0;}
   

function func1(a,b)print("esfs")average(a,b)print(type(78)) end

如何获取返回值

#include 
   
    extern "C" {
   #include "lua.h"#include "lualib.h"#include "lauxlib.h"}typedef struct haha{
   int a;int b;}haha;/* 指向lua解释器的指针 */lua_State* L;static int average(lua_State *L){
   	haha *a = (haha *)lua_topointer(L,-2);	double aa = lua_tonumber(L,-1);	//printf("%d\n",a->a);	printf("%9f\n",aa);    return 0;}int main ( int argc, char *argv[] ){
       /* 初始化Lua */    L = luaL_newstate();    /* 载入Lua基本库 */    luaL_openlibs(L);    /* 注册自定义函数 */    lua_register(L, "average", average);        luaL_loadfile(L,"avg.lua");    haha a={
   23,89};lua_pcall(L,0,0,0);      lua_getglobal(L, "func1");    lua_pushlightuserdata(L,&a);    lua_pushnumber(L,34.567999);        lua_pcall(L, 2, 2,0);      double result = lua_tonumber(L,-2);    printf("jieguoshi: %5f\n",result);    /* 执行avg.lua文件 */    luaL_dofile(L, "avg.lua");    /* 关闭Lua */    lua_close(L);    /* 暂停 */    printf( "Press enter to exit..." );    getchar();    return 0;}
   

function func1(a,b)print("esfs")average(a,b)print(type(78)) return b,bend

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