清空指定的文件夹，但不删除文件夹

<summary>

        /// 清空指定的文件夹，但不删除文件夹

        /// </summary>

        /// <param name="dir"></param>

        public static void DeleteFolder(string dir)

        {

            foreach (string d in Directory.GetFileSystemEntries(dir))

            {

                if (File.Exists(d))

                {

                    FileInfo fi = new FileInfo(d);

                    if (fi.Attributes.ToString().IndexOf("ReadOnly") != -1)

                        fi.Attributes = FileAttributes.Normal;

                    File.Delete(d);//直接删除其中的文件  

                }

                else

                {

                    DirectoryInfo d1 = new DirectoryInfo(d);

                    if (d1.GetFiles().Length != 0)

                    {

                        DeleteFolder(d1.FullName);////递归删除子文件夹

                    }

                    Directory.Delete(d);

                }

            }

        }        /// <summary>

        /// 删除文件夹及其内容

        /// </summary>

        /// <param name="dir"></param>

        public static void DeleteFolder1(string dir)

        {

            foreach (string d in Directory.GetFileSystemEntries(dir))

            {

                if (File.Exists(d))

                {

                    FileInfo fi = new FileInfo(d);

                    if (fi.Attributes.ToString().IndexOf("ReadOnly") != -1)

                        fi.Attributes = FileAttributes.Normal;

                    File.Delete(d);//直接删除其中的文件  

                }

                else

                    DeleteFolder(d);////递归删除子文件夹

                Directory.Delete(d);

            }

        }