项目中需要使用到路径处理的地方比较多，对于路径的解析和匹配有时较为繁琐，现在提供一个对路径进行解析的方法：

1.验证设置路径字符串：

/// <summary>
/// 验证设置路径字符串
/// </summary>
/// <param name="path">路径字符串</param>
/// <param name="isSequential">如果正在创建路径</param>
static public void ValidatePath(string path, bool isSequential)
{
    ValidatePath(isSequential ? path + "1" : path);
}
/// <summary>
/// 验证设置路径字符串
/// </summary>
/// <param name="path">路径字符串</param>
/// <exception cref="ArgumentException">路径无效</exception>
static public void ValidatePath(string path)
{
    if (path == null)
        throw new ArgumentException("路径不能为空");
    if (path.Length == 0)
        throw new ArgumentException("路径长度必须大于0");
    if (path[0] != '/')
        throw new ArgumentException("路径必须启动/字符");
    if (path.Length == 1) return;
    if (path[path.Length - 1] == '/')
        throw new ArgumentException("路径不能结束与/字符");
    string reason = null;
    var lastc = '/';
    var chars = path.ToCharArray();
    for (var i = 1; i < chars.Length; lastc = chars[i], i++)
    {
        var c = chars[i];
        if (c == 0) { reason = "不允许空字符 @" + i; break; }
        if (c == '/' && lastc == '/') { reason = "指定的空节点名称@" + i; break; }
        if (c == '.' && lastc == '.')
        {
            if (chars[i - 2] != '/' || ((i + 1 != chars.Length) && chars[i + 1] != '/')) continue;
            reason = "不允许的相对路径 @" + i;
            break;
        }
        if (c == '.')
        {
            if (chars[i - 1] != '/' || ((i + 1 != chars.Length) && chars[i + 1] != '/')) continue;
            reason = "不允许的相对路径 @" + i;
            break;
        }
        if ((c <= '\u0000' || c >= '\u001f') && (c <= '\u007f' || c >= '\u009F') &&
            (c <= '\ud800' || c >= '\uf8ff') && (c <= '\ufff0' || c >= '\uffff')) continue;
        reason = "无效的字符 @" + i;
        break;
    }
    if (reason != null) throw new ArgumentException(string.Format("无效的路径字符串 \"{0}\" 引起的 {1}", path, reason));
}

2.查看服务器的路径：

/// <summary>
/// 在目录到客户端的路径（如果有的话）。期望
///此功能是客户端路径已在此之前验证
////调用/函数调用
/// </summary>
/// <param name="chroot"></param>
/// <param name="clientPath">节点的路径。</param>
/// <returns>查看服务器的路径（chroot添加到客户端的路径）</returns>
static public string PrependChroot(string chroot, string clientPath)
{
    if (string.IsNullOrEmpty(chroot)) return clientPath;
    return clientPath.Length == 1 ? chroot : string.Concat(chroot, clientPath);
}

3.删除目录：

/// <summary>
/// 删除目录
/// </summary>
/// <param name="chroot"></param>
/// <param name="serverPath"></param>
/// <returns></returns>
static public string RemoveChroot(string chroot, string serverPath)
{
    if (string.IsNullOrEmpty(chroot)) return serverPath;
    return string.Compare(serverPath, chroot, StringComparison.Ordinal) == 0 ? "/" : serverPath.Substring(chroot.Length);
}