private string GetString(EventLogEntryType type,
                                 string message,
                                 string callerMemberName,
                                 string callerFilePath,
                                 int callerLineNumber)
        {
            var txt = $"[{type}][{DateTime.Now.ToString("yy/MM/dd HH:mm:ss.fff")}][{callerFilePath}][{callerMemberName}][{callerLineNumber}]\n{message}";

            if (type == EventLogEntryType.Error)
            {
                lock (LockObject)
                {
                    var dir = WpfUtil.RelativePathToAbsolutePath("log");
                    var tmp = Path.Combine(dir, $"{DateTime.Now.ToString("yyyy-MM-dd")}.log");

                    // ディレクトリを作成
                    Directory.CreateDirectory(dir);

                    File.AppendAllText(tmp, txt);
                }
            }

            return(txt);
        }