Question

我想动态调用lambda表达式，但我得到的只是methodInfo。

类似的东西：

Magic.RegisterStaticPacketHandler<TestPacket>((a, b) => { /* Do Stuff */ });

Magic class:
public void RegisterStaticPacketHandler<T>(PacketReceivedHandler<T> handler) where T : Packet
{
            //Remember the handler with: handler.GetMethodInfo()
}

后来我想调用这个方法。因为PacketReceivedHandler是一个委托，所以我可以从中获取“MethodInfo”。如果我只用：

调用这个MethodInfo

methodInfo.Invoke(obj, new object[] { packet, this });

我的ofc收到一个异常，即给定的对象（obj）不适合。设置像“NonPublic | Instance | Static”这样的BindingFlags也没有帮助。

更新

PacketReceivedHandler看起来如下：

public delegate void PacketReceivedHandler<T>(T packet, Connection connection) where T : Packet;

我把它保存在我的Magic课程中：

private Dictionary<int, Tuple<MethodInfo, object>> id_methodInfo_object = new Dictionary<int, Tuple<MethodInfo, object>>();

MethodInfo =委托
object =代表来自
id =网络资料的UID

Answer 1

除了方法之外，您还必须保存委托的Target。最简单的方法是直接存储整个代理本身而不是MethodInfo。像这样：

// Store any lambda or action or anything in their baseclass "Delegate":
Delegate act = new Action<int, int>((a, b) => Console.WriteLine(a + b));

// Dynamically invoke like this:
act.Method.Invoke(act.Target, new object[] {4, 9});

完整示例：

class Program
{
    private static List<Delegate> handlers = new List<Delegate>();
    public static void RegisterHandler<T>(Action<T> del)
    {
        handlers.Add(del);
    }
    public static void InvokeHandlers(params object[] args)
    {
        foreach (var h in handlers)
        {
            h.Method.Invoke(h.Target, args);
        }
    }

    static void Main(string[] args)
    {
        RegisterHandler((object a) => Console.WriteLine("#1:" + a));
        RegisterHandler((object a) => Console.WriteLine("#2:" + a));
        InvokeHandlers("foo");
        InvokeHandlers(1234);
    }
}

Answer 2

public void RegisterStaticPacketHandler<T>(PacketReceivedHandler<T> handler) where T : Packet
{
     _methodInfo = handler.Method;
}

请参阅MSDN

中的详细信息

MethodInfo调用中的C＃Lambda

2 个答案: