清空某个文件夹

static public void DeleteFolder(string dir)
{
    int num = 0;
    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 
            num++;
        }
        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);
        }
    }
    Console.WriteLine(dir + "共" + num + "个文件");
}