Reflaction

1. A General Fast Method Invoker (https://www.codeproject.com/Articles/14593/A-General-Fast-Method-Invoker)
public static FastInvokeHandler GetMethodInvoker(MethodInfo methodInfo)
{
    DynamicMethod dynamicMethod = new DynamicMethod(string.Empty, 
                     typeof(object), new Type[] { typeof(object), 
                     typeof(object[]) }, 
                     methodInfo.DeclaringType.Module);
    ILGenerator il = dynamicMethod.GetILGenerator();
    ParameterInfo[] ps = methodInfo.GetParameters();
    Type[] paramTypes = new Type[ps.Length];
    for (int i = 0; i < paramTypes.Length; i++)
    {
        paramTypes[i] = ps[i].ParameterType;
    }
    LocalBuilder[] locals = new LocalBuilder[paramTypes.Length];
    for (int i = 0; i < paramTypes.Length; i++)
    {
        locals[i] = il.DeclareLocal(paramTypes[i]);
    }
    for (int i = 0; i < paramTypes.Length; i++)
    {
        il.Emit(OpCodes.Ldarg_1);
        EmitFastInt(il, i);
        il.Emit(OpCodes.Ldelem_Ref);
        EmitCastToReference(il, paramTypes[i]);
        il.Emit(OpCodes.Stloc, locals[i]);
    }
    il.Emit(OpCodes.Ldarg_0);
    for (int i = 0; i < paramTypes.Length; i++)
    {
        il.Emit(OpCodes.Ldloc, locals[i]);
    }
    il.EmitCall(OpCodes.Call, methodInfo, null);
    if (methodInfo.ReturnType == typeof(void))
        il.Emit(OpCodes.Ldnull);
    else
        EmitBoxIfNeeded(il, methodInfo.ReturnType);
    il.Emit(OpCodes.Ret);
    FastInvokeHandler invoder = 
      (FastInvokeHandler)dynamicMethod.CreateDelegate(
      typeof(FastInvokeHandler));
    return invoder;
}