利用反射機制，讀取dll，並調用其中的方法

        private void UserJN(string dllName,string className,string methodName)
        {
            string classFullName = dllName + "." + className;
            Assembly ass = Assembly.Load(dllName);
            Type obj = ass.GetType(classFullName);
            MethodInfo mi = obj.GetMethod(methodName);
            object o = obj.InvokeMember(null,BindingFlags.CreateInstance,null,null,null);
            mi.Invoke(o, null);         
        }