using System;
using System.IO;

namespace WriteLog
{
    /// <summary>
    /// WriteInLog 的摘要说明。
    /// </summary>
    public class WriteInLog
    {
        private string logFileName;
        private int logFileSizes;
        
        /// <summary>
        /// 写入日志文件
        /// </summary>
        public WriteInLog()
        {
            logFileName = @"d:\logfile.txt";
        }

        /// <summary>
        /// 自动删除日志文件大小,此方法已经重载.
        /// </summary>
        /// <param name="fileSize">日志文件大小,单位KB</param>
        public WriteInLog(int fileSize):this()
        {
            if(fileSize != 0)
            {
                this.logFileSizes = fileSize * 1024;
            }
            else
            {
                this.logFileSizes = 1024;
            }
        }
        /// <summary>
        /// 日志文件完全名,如:@"d:\logfile.txt"
        /// </summary>
        public string LogFileName
        {
            set
            {
                this.logFileName = value;
            }
        }

        /// <summary>
        /// 写入日志信息
        /// </summary>
        /// <param name="msg">日志内容</param>
        /// <param name="IsAutoDelete">是否自动删除日志</param>
        public void writeInLog(string msg)
        {
            if(logFileSizes != 0)
            {
                writeInLog(msg,true);
            }
            else
            {
                writeInLog(msg,false);
            }
        }

        /// <summary>
        /// 写入日志信息
        /// </summary>
        /// <param name="msg">日志内容</param>
        /// <param name="IsAutoDelete">是否自动删除日志</param>
        private void writeInLog(string msg,bool IsAutoDelete)
        {
            try
            {
                FileInfo fileinfo=new FileInfo(logFileName);
                if(IsAutoDelete)
                {
                    if(fileinfo.Exists && fileinfo.Length >= logFileSizes)
                    {
                        fileinfo.Delete();
                    }
                }
                using(FileStream fs=fileinfo.OpenWrite())
                {
                    StreamWriter sw=new StreamWriter(fs);
                    sw.BaseStream.Seek(0,SeekOrigin.End);
                    sw.WriteLine("=====================================");
                    sw.Write("添加日期为:" + DateTime.Now.ToString() +"\r\n");
                    sw.Write("日志内容为:" + msg + "\r\n");
                    sw.WriteLine("=====================================");
                    sw.Flush();
                    sw.Close();
                }
            }
            catch(Exception ex)
            {
                ex.ToString();
            }
        }
    
    }
}