Question

我试图在C＃中使用Lua（C），我已经导入了一些函数来测试它，一切似乎都有效，直到我尝试从Lua调用C＃函数。

static void Main(string[] args)
{
    var L = Lua.luaL_newstate();
    Lua.luaL_openlibs(L);
    Lua.lua_register(L, "test", Test);
    Lua.luaL_dostring(L, "test()");
}

static int Test(IntPtr L)
{
    Console.WriteLine("Test from lua->C#");
    return 0;
}

如果我运行此代码，我会收到测试消息，但在此之后它会抛出一个AccessViolationException：

// #define luaL_dostring(L, s) (luaL_loadstring(L, s) || lua_pcall(L, 0, LUA_MULTRET, 0))
public static int luaL_dostring(IntPtr L, string s)
{
    if (luaL_loadstring(L, s) != 0)
        return 1;

    if (lua_pcall(L, 0, LUA_MULTRET, 0) != 0) // <<<<<<<<<<<<<<<<<<<<<<<<
        return 1;

    return 0;
}

这是我的整个导入代码：

public static class Lua
{
    public const int LUA_MULTRET = -1;

    //[return: MarshalAs(UnmanagedType.SysInt)]
    public delegate int LuaNativeFunction(IntPtr L);

    [DllImport("lua51.dll", CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    public static extern IntPtr luaL_newstate();

    [DllImport("lua51.dll", CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    public static extern void luaL_openlibs(IntPtr L);

    [DllImport("lua51.dll", CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    public static extern int luaL_loadbuffer(IntPtr L, [MarshalAs(UnmanagedType.LPStr)] string buff, int size, [MarshalAs(UnmanagedType.LPStr)] string name);

    // LUA_API int lua_resume (lua_State *L, int nargs)
    [DllImport("lua51.dll", CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    public static extern int lua_resume(IntPtr L, int nargs);

    // static int lua_pcall(lua_State*L,int nargs,int nresults,int errfunc)
    [DllImport("lua51.dll", CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    public static extern int lua_pcall(IntPtr L, int nargs, int nresults, int errfunc);

    // static void lua_pushcclosure(lua_State*L,lua_CFunction fn,int n)
    [DllImport("lua51.dll", CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    public static extern int lua_pushcclosure(IntPtr L, LuaNativeFunction fn, int n);

    // static void lua_setfield(lua_State*L,int idx,const char*k);
    [DllImport("lua51.dll", CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    public static extern int lua_setfield(IntPtr L, int idx, [MarshalAs(UnmanagedType.LPStr)] string k);

    // LUALIB_API int (luaL_loadstring) (lua_State *L, const char *s)
    public static int luaL_loadstring(IntPtr L, string s)
    {
        return luaL_loadbuffer(L, s, s.Length, s);
    }

    // #define luaL_dostring(L, s) (luaL_loadstring(L, s) || lua_pcall(L, 0, LUA_MULTRET, 0))
    public static int luaL_dostring(IntPtr L, string s)
    {
        if (luaL_loadstring(L, s) != 0)
            return 1;

        if (lua_pcall(L, 0, LUA_MULTRET, 0) != 0)
            return 1;

        return 0;
    }

    // #define lua_register(L,n,f) (lua_pushcfunction(L, (f)), lua_setglobal(L, (n)))
    public static void lua_register(IntPtr L, string n, LuaNativeFunction f)
    {
        lua_pushcfunction(L, f);
        lua_setglobal(L, n);
    }

    // #define lua_pushcfunction(L,f)   lua_pushcclosure(L, (f), 0)
    public static void lua_pushcfunction(IntPtr L, LuaNativeFunction f)
    {
        lua_pushcclosure(L, f, 0);
    }

    // #define lua_setglobal(L,s)lua_setfield(L,(-10002),(s))
    public static void lua_setglobal(IntPtr L, string s)
    {
        lua_setfield(L, -10002, s);
    }
}

因为我读到这可能是由委托的返回值中的类型不匹配引起的：我运行的是Windows 7 x64，Lua dll是x86，项目也设置为使用x86。我还尝试为LuaNativeFunction设置一个返回元帅，因为这是在其他地方建议的，但这并没有改变任何东西。

[return: MarshalAs(UnmanagedType.I4)]
public delegate int LuaNativeFunction(IntPtr L);

有人知道问题可能是什么吗？

更新：使用带有x64目标的x64 Lua lib解决了它，所以我猜这是问题，但我不太明白为什么。

Answer 1

Lua DLL使用CDecl调用约定进行编译，您需要在所有DllImport属性上指定它，并且所有委托都用作回调。因此，例如，您的LuaNativeFunction委托需要声明为：

[UnmanagedFunctionPointer(System.Runtime.InteropServices.CallingConvention.Cdecl‌)]
[return: MarshalAs(UnmanagedType.I4)]
public delegate int LuaNativeFunction(IntPtr L);

此致

从Lua调用C＃时出现AccessViolationException

1 个答案: