[原]简单的写日志公共类

引用命名空间：
using System.IO;

    public class WriteLog
    {
        public static readonly WriteLog WriteLogInstance = new WriteLog();
        public void Init(string filePath)
        {
            Init(filePath,string.Empty,0);
        }
        public void Init(string filePath,int maxSize_KB)
        {
            Init(filePath, string.Empty, maxSize_KB);
        }
        public void Init(string filePath,string fileName,int maxSize_KB)
        {
            _logFilePath = filePath;
            _logFileName = fileName;
            _logMaxSize = maxSize_KB;
        }

        private string _logFilePath;
        public string LogFilePath
        {
            get 
            {
                 WriteLogInstance._logFilePath = string.IsNullOrEmpty(WriteLogInstance._logFilePath) ? 
                    AppDomain.CurrentDomain.SetupInformation.ApplicationBase + System.IO.Path.DirectorySeparatorChar : WriteLogInstance._logFilePath;
                return WriteLogInstance._logFilePath;
            }
            set { WriteLogInstance._logFilePath = value; }
        }

        private string _logFileName;
        public string LogFileName
        {
            get 
            {
                WriteLogInstance._logFileName = string.IsNullOrEmpty(WriteLogInstance._logFileName) ? "Applog.log" : WriteLogInstance._logFileName;
                return WriteLogInstance._logFileName; 
            }
            set { WriteLogInstance._logFileName = value; }
        }

        private int _logMaxSize;
        /**//// <summary>
        /// 日志文件大小，单位KB
        /// 最大为5*1024KB，默认为1024KB。
        /// </summary>
        public int LogMaxSize
        {
            get 
            {
                WriteLogInstance._logMaxSize = (WriteLogInstance._logMaxSize <= 0 || WriteLogInstance._logMaxSize > 5120) ? 1024 : WriteLogInstance._logMaxSize;
                return WriteLogInstance._logMaxSize; 
            }
            set { WriteLogInstance._logMaxSize = value; }
        }


        private object _objLock = new object();
        public void WriteToLog(string[] content)
        {
            lock (_objLock)
            {
                string folder = LogFilePath;
                string logFile = LogFileName;
                string filePath = folder + logFile;
                if (!Directory.Exists(folder))
                    Directory.CreateDirectory(folder);

                System.IO.FileInfo info = new System.IO.FileInfo(filePath);

                if (info.Exists)
                {
                    int maxSize = LogMaxSize*1024;//转换为字节

                    if (info.Length > maxSize)
                    {
                        string bkPath = DateTime.Now.ToString("yyyyMMddHHmmss") + "_" + logFile;
                        System.IO.File.Move(filePath, folder + bkPath);
                    }
                }

                System.IO.StreamWriter writer = new System.IO.StreamWriter(filePath, true,System.Text.Encoding.UTF8);
                foreach (string line in content)
                {
                    writer.WriteLine(line);
                }
                writer.Close();
            }
        }

        public void WriteToLog(string message)
        {
            string[] messages = new string[1] { message};
            WriteToLog(messages);
        }
        public void WriteErrorInfo(string funcName, string message)
        {
            //写入本地log中。
            List<string> messageList = new List<string>();
            messageList.Add("--------------------------------------");
            messageList.Add(System.DateTime.Now.ToString());
            messageList.Add(funcName);
            messageList.Add(message);
            WriteLogInstance.WriteToLog(messageList.ToArray());
        }
    }

 使用时：
首先可以：WriteLog.WriteLogInstance.Init(...);

然后：向日志中写信息，WriteLog.WriteLogInstance.WriteToLog(message);
或向日志中写异常信息：WriteLog.WriteLogInstance.WriteErrorInfo(...);