c#文件助手类分享(读取文件内容 操作日志文件)

        /// <summary>
        /// 文件名是否满足filePattern格式。
        /// </summary>
        /// <param name="fileName"></param>
        public static bool IsMatched(string fileName, string filePattern)
        {
            if (string.IsNullOrWhiteSpace(fileName))
            {
                return false;
            }
            if (string.IsNullOrWhiteSpace(filePattern))
            {
                return false;
            }
            Regex regex = new Regex(filePattern, RegexOptions.IgnoreCase);
            return regex.IsMatch(fileName);
        }

        /// <summary>
        /// 读取文件内容
        /// </summary>
        /// <param name="file"></param>
        /// <returns></returns>
        public static string ReadAllText(string filePath)
        {
            if (string.IsNullOrWhiteSpace(filePath) || File.Exists(filePath) == false)
            {
                return string.Empty;
            }
            return File.ReadAllText(filePath);
        }
        /// <summary>
        /// 删除文件
        /// </summary>
        /// <param name="filePath"></param>
        public static bool Delete(string filePath)
        {
            if (string.IsNullOrWhiteSpace(filePath))
            {
                return false;
            }
            if (!File.Exists(filePath))
            {
                return false;
            }
            File.Delete(filePath);
            return !File.Exists(filePath);
        }
        /// <summary>
        /// 删除目录下所有过期文件
        /// </summary>
        /// <param name="directory"></param>
        /// <param name="expiredDays"></param>
        public static int ClearExpiredFiles(string directory, int expiredDays)
        {
            if (!Directory.Exists(directory))
            {
                return 0;
 &nb