lua 调用 c# delegate 报错

[wulei]

我在拿第三方的一个besthttp做了一些调用使用测试，有些疑问，请教一下：

这个是c# code

namespace BestHTTP.WebSocket
{
    public delegate void OnWebSocketOpenDelegate(WebSocket webSocket);
    public delegate void OnWebSocketMessageDelegate(WebSocket webSocket, string message);
    public delegate void OnWebSocketBinaryDelegate(WebSocket webSocket, byte[] data);
    public delegate void OnWebSocketClosedDelegate(WebSocket webSocket, UInt16 code, string message);
    public delegate void OnWebSocketErrorDelegate(WebSocket webSocket, Exception ex);
    public delegate void OnWebSocketErrorDescriptionDelegate(WebSocket webSocket, string reason);

#if (!UNITY_WEBGL || UNITY_EDITOR)
    public delegate void OnWebSocketIncompleteFrameDelegate(WebSocket webSocket, WebSocketFrameReader frame);
#else
    delegate void OnWebGLWebSocketOpenDelegate(uint id);
    delegate void OnWebGLWebSocketTextDelegate(uint id, string text);
    delegate void OnWebGLWebSocketBinaryDelegate(uint id, IntPtr pBuffer, int length);
    delegate void OnWebGLWebSocketErrorDelegate(uint id, string error);
    delegate void OnWebGLWebSocketCloseDelegate(uint id, int code, string reason);

    /// <summary>
    /// States of the underlying browser's WebSocket implementation's state. It's available only in WebGL builds.
    /// </summary>
    public enum WebSocketStates : byte
    {
        Connecting = 0,
        Open       = 1,
        Closing    = 2,
        Closed     = 3
    };
#endif

    public sealed class WebSocket
    {
#region Properties

        /// <summary>
        /// The connection to the WebSocket server is open.
        /// </summary>
        public bool IsOpen
        {
            get
            {
#if (!UNITY_WEBGL || UNITY_EDITOR)
                return webSocket != null && !webSocket.IsClosed;
#else
                return ImplementationId != 0 && WS_GetState(ImplementationId) == WebSocketStates.Open;
#endif
            }
        }

#if (!UNITY_WEBGL || UNITY_EDITOR)
        /// <summary>
        /// Set to true to start a new thread to send Pings to the WebSocket server
        /// </summary>
        public bool StartPingThread { get; set; }

        /// <summary>
        /// The delay between two Pings in millisecs. Minimum value is 100, default is 1000.
        /// </summary>
        public int PingFrequency { get; set; }

        /// <summary>
        /// The internal HTTPRequest object.
        /// </summary>
        public HTTPRequest InternalRequest { get; private set; }

        /// <summary>
        /// IExtension implementations the plugin will negotiate with the server to use.
        /// </summary>
        public IExtension[] Extensions { get; private set; }
#endif

        /// <summary>
        /// Called when the connection to the WebSocket server is estabilished.
        /// </summary>
        public OnWebSocketOpenDelegate OnOpen;

        /// <summary>
        /// Called when a new textual message is received from the server.
        /// </summary>
        public OnWebSocketMessageDelegate OnMessage;

        /// <summary>
        /// Called when a new binary message is received from the server.
        /// </summary>
        public OnWebSocketBinaryDelegate OnBinary;

        /// <summary>
        /// Called when the WebSocket connection is closed.
        /// </summary>
        public OnWebSocketClosedDelegate OnClosed;

这个是lua code

function awake()
print("awake...")
end

local ws = nil
-- local url = "ws://echo.websocket.org"
local url = "ws://115.29.193.48:8088"

function start()
	print("websocket lua start...")
	ws = CS.BestHTTP.WebSocket.WebSocket(CS.System.Uri(url))
	print(ws.IsOpen)

	ws:OnOpen('+', function(ws)
		print("nice!!!~~~~")
	end)
	ws:Open()
end

function update()
	-- print(ws.IsOpen)
end

function ondestroy()
    print("websocket lua destroy")
end

结果如下：

LuaException: [string "LuaBehaviour"]:15: attempt to call a nil value (method 'OnOpen')
stack traceback:
	[string "LuaBehaviour"]:15: in function <[string "LuaBehaviour"]:10>
XLua.LuaEnv.ThrowExceptionFromError (Int32 oldTop) (at Assets/xLua/Src/LuaEnv.cs:360)
XLuaGenDelegateImpl0.Invoke1 ()
LuaBehaviour.Start () (at Assets/_LFramework/Scripts/Common/LuaBehaviour.cs:70)

如果我在update中一直打印：ws.IsOpen，是看得出他在调用链接，最后返回链接上的，但是调用delegate就报错了，是否是我使用者的问题？

[Jayatubi]

delegate可以用'+'么？我以为只有event可以那样写。

[chexiongsheng]

ws.OnOpen = ws.OnOpen + function() end

另外，你那个delegate要加CSharpCallLua

[chexiongsheng]

其实在教程都有，最好去看看

[wulei]

不好意思，教程里面我看歪了。
把delegate的+链接和event混了。

[wulei]

@chexiongsheng

LuaException: [string "WebsocketTest.lua"]:24: attempt to perform arithmetic on a nil value (field 'OnClosed')
stack traceback:
	[string "WebsocketTest.lua"]:24: in function <[string "WebsocketTest.lua"]:10>
XLua.LuaEnv.ThrowExceptionFromError (Int32 oldTop) (at Assets/xLua/Src/LuaEnv.cs:360)
XLuaGenDelegateImpl0.Invoke2 ()
LuaBehaviour.Start () (at Assets/_LFramework/Scripts/Common/LuaBehaviour.cs:70)

教程里面中的是ok的，但是这个是说 on a nil value，已经在delegate中加入CSharpCallLua，而且我调用ws.IsOpen的bool值不会有问题

[chexiongsheng]

你要先判空，空的话直接OnOpen=function。
貌似c#下也是会报错的吧，如果左值为null的话