C# 处理unhandled Exception方式如下：

1. 在程序的Main()方法中增加如下代码。
   <pre>//处理线程未处理的异常
   Application.ThreadException += new System.Threading.ThreadExceptionEventHandler(Application_ThreadException);
   //处理系统未处理的异常
   AppDomain.CurrentDomain.UnhandledException += new UnhandledExceptionEventHandler(CurrentDomain_UnhandledException);
   //运行程序
   Application.Run(new frmServerMain());
   </pre>
2. 方法：

static void Application_ThreadException(object sender, System.Threading.ThreadExceptionEventArgs e)
        {
            string str = "";
            Exception error = e.Exception as Exception;
            if (error != null)
            {
                str = string.Format("Application unhandled exception.\nExceptionType:{0}\nException Message: {1}\n StackTrace:{2}\n",
                     error.GetType().Name, error.Message, error.StackTrace);
            }
            else
            {
                str = string.Format("Application Thread Exception Msg:{0}", e);
            }
            WriteErrInfo(str);
        }
       static void CurrentDomain_UnhandledException(object sender, UnhandledExceptionEventArgs e)
        {
            string str = "";
            Exception error = e.ExceptionObject as Exception;
            if (error != null)
            {
                str = string.Format("Application UnhandledException:{0};\nStackTrace:{1}", error.Message, error.StackTrace);
            }
            else
            {
                str = string.Format("Application UnhandledError:{0}", e);
            }
            WriteErrInfo(str);
        }
        static void WriteErrInfo(string vErrMsg)
        {
            using (System.IO.FileStream fs = new System.IO.FileStream(Application.StartupPath + "\\Log\\TestException.log",
                System.IO.FileMode.Append, System.IO.FileAccess.Write))
            {
                using (System.IO.StreamWriter w = new System.IO.StreamWriter(fs,System.Text.Encoding.UTF8))
                {
                    w.WriteLine(vErrMsg); DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss");
                }
            }
        }

详细分析可参见：
http://www.cnblogs.com/eaglet/archive/2009/02/17/1392191.html