根据网上查询，写了一个如下的方法：
public bool AddpathPower(string pathname, string username, string power)
{
try
{
DirectoryInfo dirinfo = new DirectoryInfo(pathname);
if ((dirinfo.Attributes & FileAttributes.ReadOnly) != 0)
{
dirinfo.Attributes = FileAttributes.Normal;
}
//取得访问控制列表
DirectorySecurity dirsecurity = dirinfo.GetAccessControl();
switch (power)
{
case "FullControl":
dirsecurity.AddAccessRule(new FileSystemAccessRule(username, FileSystemRights.FullControl, InheritanceFlags.ObjectInherit, PropagationFlags.InheritOnly, AccessControlType.Allow));
break;
case "ReadOnly":
dirsecurity.AddAccessRule(new FileSystemAccessRule(username, FileSystemRights.Read, AccessControlType.Allow));
break;
&am