日志帮助类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Configuration;
using System.Reflection;

namespace LogHelper.Common
{
    public class LogHelper
    {
        private string logFile = "";
        /// <summary>
        /// 不带参数的构造函数
        /// </summary>
        public LogHelper()
        {
            try
            {
                string logPath = Path.Combine(System.Environment.CurrentDirectory,DateTime.Now.ToString("yyyyMM"));
                logFile = Path.Combine(logPath,DateTime.Now.ToString("yyyyMMdd") + ".txt");
                if (!Directory.Exists(logPath))
                    Directory.CreateDirectory(logPath);

                if (!File.Exists(logFile))
                    File.Create(logFile);
            }
            catch
            {
            }
        }
        /// <summary>
        /// 带参数的构造函数
        /// </summary>
        /// <param name="logFile"></param>
        public LogHelper(string logFile)
        {
            try
            {
                this.logFile = logFile;
                if (!File.Exists(logFile))
                {
                    File.Create(logFile);
                }
            }
            catch { }

        }
        /// <summary>
        /// 追加一条信息
        /// </summary>
        /// <param name="text"></param>
        public void Write(string text)
        {
            try
            {
                using (StreamWriter sw = new StreamWriter(logFile, true, Encoding.UTF8))
                {
                    sw.Write(DateTime.Now.ToString("[yyyy-MM-dd HH:mm:ss] ") + text);
                }
            }
            catch { }
        }
        /// <summary>
        /// 追加一条信息
        /// </summary>
        /// <param name="logFile"></param>
        /// <param name="text"></param>
        public void Write(string logFile, string text)
        {
            try
            {
                using (StreamWriter sw = new StreamWriter(logFile, true, Encoding.UTF8))
                {
                    sw.Write(DateTime.Now.ToString("[yyyy-MM-dd HH:mm:ss] ") + text);
                }
            }
            catch { }
        }
        /// <summary>
        /// 追加一行信息
        /// </summary>
        /// <param name="text"></param>
        public void WriteLine(string text)
        {
            try
            {
                text += "\r\n";
                using (StreamWriter sw = new StreamWriter(logFile, true, Encoding.UTF8))
                {
                    sw.Write(DateTime.Now.ToString("[yyyy-MM-dd HH:mm:ss] ") + text);
                }
            }
            catch { }
        }
        /// <summary>
        /// 追加一行信息
        /// </summary>
        /// <param name="logFile"></param>
        /// <param name="text"></param>
        public void WriteLine(string logFile, string text)
        {
            try
            {
                text += "\r\n";
                using (StreamWriter sw = new StreamWriter(logFile, true, Encoding.UTF8))
                {
                    sw.Write(DateTime.Now.ToString("[yyyy-MM-dd HH:mm:ss] ") + text);
                }
            }
            catch { }
        }
    }
}

 LogHelper.Common.LogHelper logHelper = new Common.LogHelper();

logHelper.WriteLine("你好");

string logPath = Path.Combine(System.Environment.CurrentDirectory,DateTime.Now.ToString("yyyyMM"));
                logFile = Path.Combine(logPath,DateTime.Now.ToString("yyyyMMdd") + ".txt");