C# 设置文件目录只读属性，取消只读属性

/// <summary>
    /// 文件帮助类
    /// </summary>
    public class FileHelper
    {
        /// <summary>
        /// 设置目录只读、取消只读
        /// </summary>
        /// <param name="dirPath"></param>
        /// <param name="readOnly"></param>
        public static void SetDirectoryReadOnly(string dirPath, bool readOnly)
        {
            System.IO.DirectoryInfo dir = new System.IO.DirectoryInfo(dirPath);

            if (readOnly)
                dir.Attributes = System.IO.FileAttributes.ReadOnly & System.IO.FileAttributes.Directory;
            else
                dir.Attributes = System.IO.FileAttributes.Normal & System.IO.FileAttributes.Directory;

        }

        /// <summary>
        /// 设置文件只读、取消只读
        /// </summary>
        /// <param name="filePath"></param>
        /// <param name="readOnly"></param>
        public static void SetFileReadOnly(string filePath, bool readOnly)
        {
            if (readOnly)
                System.IO.File.SetAttributes(filePath, System.IO.FileAttributes.ReadOnly);
            else
                System.IO.File.SetAttributes(filePath, System.IO.FileAttributes.Normal);
        }

        /// <summary>
        /// 判断文件是否只读
        /// </summary>
        /// <param name="filePath"></param>
        /// <returns></returns>
        public static bool IsReadOnly(string filePath)
        {
            return System.IO.File.GetAttributes(filePath).HasFlag(System.IO.FileAttributes.ReadOnly);
        }

    }