asp.net mvc 防止开放重定向

/// <summary>

/// 防止开发重定向，篡改returnurl

/// </summary>

/// <param name="request"></param>

/// <param name="url"></param>

/// <returns></returns>

private static bool IsLocalUrl(string url)

{

      if (string.IsNullOrEmpty(url))

      {

            return false;

       }

       Uri absoluteUri;

       if (Uri.TryCreate(url, UriKind.Absolute, out absoluteUri))

       {

             return String.Equals(HttpContext.Current.Request.Url.Host, absoluteUri.Host, StringComparison.OrdinalIgnoreCase);

        }

         else

        {

                bool isLocal = !url.StartsWith("http:", StringComparison.OrdinalIgnoreCase) && !url.StartsWith("https:", StringComparison.OrdinalIgnoreCase) && Uri.IsWellFormedUriString(url, UriKind.Relative);

                return isLocal;

         }

 }