public class WriteLog 
    { 
        /// <summary> 
        /// 创建日志文件 
        /// </summary> 
        /// <param name="ex">异常类</param> 
        public static void CreateLog(Exception ex) 
        { 
            string path = Application.StartupPath+"\\log"; 
            if (!Directory.Exists(path)) 
            { 
                //创建日志文件夹 
                Directory.CreateDirectory(path); 
            } 
            //发生异常每天都创建一个单独的日子文件[*.log],每天的错误信息都在这一个文件里。方便查找 
            path += "\\"+DateTime.Now.ToShortDateString() + ".log"; 
            WriteLogInfo(ex, path); 
        } 
        /// <summary> 
        /// 写日志信息 
        /// </summary> 
        /// <param name="ex">异常类</param> 
        /// <param name="path">日志文件存放路径</param> 
        private static void WriteLogInfo(Exception ex, string path) 
        { 
            using (StreamWriter sw = new StreamWriter(path, true, Encoding.Default)) 
            { 
                sw.WriteLine("*****************************************【" 
                               + DateTime.Now.ToLongTimeString() 
                               + "】*****************************************"); 
                if (ex != null) 
                { 
                    sw.WriteLine("【ErrorType】" + ex.GetType()); 
                    sw.WriteLine("【TargetSite】" + ex.TargetSite); 
                    sw.WriteLine("【Message】" + ex.Message); 
                    sw.WriteLine("【Source】" + ex.Source); 
                    sw.WriteLine("【StackTrace】" + ex.StackTrace); 
                } 
                else 
                { 
                    sw.WriteLine("Exception is NULL"); 
                } 
                sw.WriteLine(); 
            } 
        } 
    }