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    Lua编程示例(五): C语言对Lua表的读取和添加

    作者:admin 时间:2021-02-03 18:18

    #include "stdafx.h"
    
    lua_State *L;
    
    
    void load_lua(char *filename){
     L=luaL_newstate();
     luaL_openlibs(L);
     if((luaL_loadfile(L,filename) || lua_pcall(L,0,0,0))!= 0){
     luaL_error(L,"loadfile error! \n %s",lua_tostring(L,-1));
     }
    }
    
    double getfield(lua_State *L,char * key){
     double res;
     //默认栈顶是table,将key入栈
     lua_pushstring(L,key);
     lua_gettable(L,-2);  //查找键值为key的元素,置于栈顶
     if(!lua_isnumber(L,-1)){
     luaL_error(L,"num get error! %s\n",lua_tostring(L,-1));
     }
     res = lua_tonumber(L,-1);
     lua_pop(L,1); //删掉产生的查找结果
     return res;
    }
    void setfield(lua_State *L,char *key,double value){
     //默认栈顶是table
     lua_pushstring(L,key);
     lua_pushnumber(L,value);
     lua_settable(L,-3); //将这一对键值设成元素
    }
    
    struct mycolor{
     char *name;
     unsigned char red,green,blue;
    }Color[]={
     {"WIETH",1,1,1},
     {"BLACK",0,0,0},
     {"BLUE",0,0,1}
    };
    //先创建一个空的栈,填入元素,用lua_setglobal弹出表,并赋成全局变量
    void setcolor(lua_State *L,struct mycolor col){
     lua_newtable(L);
     setfield(L,"r",col.red);
     setfield(L,"g",col.green);
     setfield(L,"b",col.blue);
     lua_setglobal(L,col.name);
    }
    
    void getcolor(lua_State *L,char *key){
     lua_getglobal(L,key);
     if(!lua_istable(L,-1)){
     luaL_error(L,"'background' is not a table! %s\n",lua_tostring(L,-1));
     }
     double red;
     double green;
     double blue; 
     red = getfield(L,"r");
     blue = getfield(L,"b");
     green = getfield(L,"g");
     printf("The %s color : red = %.2f ,green = %.2f ,blue = %.2f\n",key,red,green,blue);
    }
    
    int _tmain(int argc, _TCHAR* argv[])
    {
     load_lua("test.lua");
     getcolor(L,"background");
     int i = 0;
     while(Color[i].name != NULL){
     setcolor(L,Color[i]);
     i++;
     }
     getcolor(L,"WIETH");
     getcolor(L,"BLUE");
     return 0;
    }
    

    test.lua 中就一行代码:

    复制代码 代码如下:

    background = {r=1,g=0.5,b=0.7} 

    运行输出结果为:

    The background color : red = 1.00 ,green = 0.50 ,blue = 0.70
    The WIETH color : red = 1.00 ,green = 1.00 ,blue = 1.00
    The BLUE color : red = 0.00 ,green = 0.00 ,blue = 1.00

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