using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Web;

namespace BMCMInterface
{
    public class LogFiles
    {
        private static string _fileName;
        private static Dictionary<long, long> lockDic = new Dictionary<long, long>();
        ///
 
 <summary> 
        /// 獲取或設定檔名稱 
        /// </summary> 
        public string FileName
        {
            get { return _fileName; }
            set { _fileName = value; }
        }

        ////<summary> 
        /// 建構函式 
        /// </summary> 
        /// <param name="byteCount">每次開闢位數大小，這個直接影響到記錄檔案的效率</param>
 
 
        /// <param name="fileName">檔案全路徑名</param> 
        public LogFiles(string fileName)
        {
            _fileName = fileName;
        }

        /// <summary> 
        /// 建構函式 
        /// </summary>
        public LogFiles()
        { }

        /// <summary> 
        /// 建立檔案 
 

        /// </summary> 
        /// <param name="fileName"></param> 
        public void Create()
        {
            if (System.IO.File.Exists(_fileName))
            {
                FileInfo logfileinfo = new FileInfo(_fileName);
                if (logfileinfo.Length > 10240000)
                {
                    GenerateNewLogFileName();
                }
            }
        }

        /// <summary> 
        /// 寫入文字 
        /// </summary> 
        /// <param name="content">文字內容</param> 
        private void Write(string content, string newLine, string time)
        {
            if (string.IsNullOrEmpty(_fileName))
            {
                GenerateNewLogFileName();
            }

            Create();

            using (System.IO.FileStream fs = new System.IO.FileStream(_fileName, System.IO.FileMode.OpenOrCreate, System.IO.FileAccess.ReadWrite, System.IO.FileShare.ReadWrite, 8, System.IO.FileOptions.Asynchronous))
            {
                //Byte[] dataArray = System.Text.Encoding.ASCII.GetBytes(System.DateTime.Now.ToString() + content + "/r/n"); 
                Byte[] dataArray = System.Text.Encoding.Default.GetBytes(time + "  " + content + newLine);
                bool flag = true;
                long slen = dataArray.Length;
                long len = 0;
                while (flag)
                {
                    try
                    {
                        if (len >= fs.Length)
                        {
                            fs.Lock(len, slen);
                            lockDic[len] = slen;
                            flag = false;
                        }
                        else
                        {
                            len = fs.Length;
                        }
                    }
                    catch (Exception ex)
                    {
                        while (!lockDic.ContainsKey(len))
                        {
                            len += lockDic[len];
                        }
                    }
                }
                fs.Seek(len, System.IO.SeekOrigin.Begin);
                fs.Write(dataArray, 0, dataArray.Length);
                fs.Close();
            }
        }
        /// <summary> 
        /// 寫入檔案內容 
        /// </summary> 
        /// <param name="content"></param> 
        public void WriteLine(string content)
        {
            this.Write(content, System.Environment.NewLine, DateTime.Now.ToString());
        }
        /// <summary> 
        /// 寫入檔案 
        /// </summary> 
        /// <param name="content"></param> 
        public void Write(string content)
        {
            this.Write(content, "", "");
        }

        ///<summary>
        ///構造log檔名
        ///</summary>
        private void GenerateNewLogFileName()
        {
            //generate a new log file name
            string strDateTimeString = string.Format("{0:yyyyMMddHHmm}", System.DateTime.Now);
            string LogFile_Name = strDateTimeString + ".log";
            _fileName = AppDomain.CurrentDomain.BaseDirectory + LogFile_Name;
        }

    }

}

//賦值：LogFile.FileName =AppDomain.CurrentDomain.BaseDirectory + "logText.log";
 //呼叫：LogFile.WriteLine("獲取異常：" + ex.Message + sql);