访问从Lua到C的嵌套表以获取值

Question

您好，我正在尝试访问从Lua发送到C的嵌套表。该表是：

arg =
{
  MagicNumber =  {MagicNumber, 0},    
  ProdNum   =  {ProdNum,    1}, 
  LetterR   =  {LetterR,      0xc}, 
  Revision  =  {Revision,    0xd},  
  Space1    =  {Space1,     0xe}, 
  MnfctrCode  =  {MnfctrCode,  0xf},  
  Hyphen1   =  {Hyphen1,      0x12},
  ZeroCode  =  {ZeroCode, 0x13},    
  Hyphen2   =  {Hyphen2,      0x15},
  MnfctrMnth  =  {MnfctrMnth,  0x16}, 
  MnfctrYear  =  {MnfctrYear,  0x18}, 
  SerialNum =  {SerialNum,  0x1a},
  Space2    =  {Space2,     0x1e},
  ChkSum    =  {ChkSum,      0x1f}, 
}

里面的表都是整数值，表中的键是一个字符串。我的代码片段如下：

lua_pushnil(L);

while(lua_next(L, -2) != 0)
{
    field = lua_tostring(L, -2);
    printf("\n %d field = %s", i, field);
    wrData[i-1] = lua_tonumber(L,-1);
    printf("\n data = 0x%x", wrData[i-1]);
    lua_pop(L, -1);
    i++;
}

我是否遗漏了什么，因为我得到的值是0x0。