Log

internal abstract class ILogger {
        protected ILogger() {
        }

        public virtual void Close() {
        }

        //protected string Time() {
        //    TimeSpan span = (TimeSpan)(DateTime.Now - Application.ProgramStartTime);
        //    return (span.Hours.ToString().PadLeft(2, '0') + ":" + span.Minutes.ToString().PadLeft(2, '0') + ":" + span.Seconds.ToString().PadLeft(2, '0') + "." + span.Milliseconds.ToString().PadLeft(3, '0'));
        //}

        public abstract void Write(params string[] msg);

        public virtual void WriteRaw(string msg) {
            this.Write(new string[] { msg });
        }
    }

    internal abstract class FileLogger : ILogger {
        private StreamWriter file;
        protected object locker = new object();

        public FileLogger(string filename) {
            lock (this.locker) {
                this.file = new StreamWriter(filename);
                this.file.AutoFlush = true;
            }
        }

        public override void Close() {
            this.file.Close();
        }

        public override void WriteRaw(string msg) {
            lock (this.locker) {
                this.file.Write(msg);
            }
        }
    }

    internal class TextLogger : FileLogger {
        public TextLogger(string log)
            : base(log + ".txt") {
        }

        public override void Write(params string[] msg) {
            lock (base.locker) {
                StringBuilder builder = new StringBuilder();
                builder.Append(DateTime.Now.ToString()).Append("| ").Append(msg[0]).Append("\r\n");
                for (int i = 1; i < msg.Length; i++) {
                    builder.Append("            | ").Append(msg[i]).Append("\r\n");
                }

                this.WriteRaw(builder.ToString());
            }
        }
    }

---------------------------------------------------
public static void LogInit(){
            if (!logInited) {
                logInited = true;
                if (!Directory.Exists(ApplicationDataFolder + "Logs")) {
                    Directory.CreateDirectory(ApplicationDataFolder + "Logs");
                }

                applicationLog = new TextLogger(ApplicationDataFolder + "Logs/ApplicationLog");
                applicationLog.Write(new string[] { "Date: " + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") });
                applicationLog.Write(new string[] { "assembly version: " + typeof(App).Assembly.GetName() });
                applicationLog.Write(new string[] { "PreInit log: " + DateTime.Now.ToString("HH:mm:ss") });
                applicationLog.Write(new string[] { preInitLog.ToString() });
            }
        }

        public static void Log(params string[] msg) {
            if (!logInited) {
                preInitLog.Append("PreInit[" + DateTime.Now.ToString("HH:mm:ss") + "]|");
                foreach (string str in msg) {
                    preInitLog.Append(str + "\r\n");
                }
            } else {
                applicationLog.Write(msg);
            }
        }