我有一个方法，我在我的网络服务Correct()中调用 - 每当用户得到正确的内容时，我调用此方法并递增GameInfo.correct。在这个方法中，我还想增加登录用户计数器属性。
public void Correct()
{
GameInfo.correct++;
The_Factory_Chante.Models.Learner learner;
using (The_Factory_Chante.Models.The_FactoryDBContext db2 = new The_Factory_Chante.Models.The_FactoryDBContext())
{
learner = db2.Learners.ToList().FirstOrDefault(a => a.learnerID == User.Identity.GetUserId());
learner.counter++;
}
}
但是我收到以下错误：
＆＃39; System.Security.Principal.IIdentity＆＃39;不包含＆＃39; GetUserId＆＃39;的定义没有扩展方法＆＃39; GetUserId＆＃39;接受第一个类型为System.Security.Principal.IIdentity＆＃39;可以找到（你错过了使用指令或程序集引用吗？）
答案 0 :(得分：0)
我使用cookies。下面是C＃中的cookie类。它还支持加密。
// Constructor:
// Utility.Cookies cookies = new Cookies(Request,Response);
// Public methods:
// Delete(string cookieToDelete) - Deletes a cookie.
// Set(string cookieName, string cookieValue, DateTime expireTime) - Sets a cookie
// Get(string cookieName) - Gets the value of a cookie
// GetEncrypted(string cookieName) - Gets the value of a cookie and decrypts it.
// SetEncrypted(string cookieName, string cookieValue, DateTime expireTime) - Sets the encrypted value of a cookie
using System;
using System.Text;
using System.Web;
using System.Security.Cryptography;
using System.IO;
namespace Utility
{
/// <summary>
/// Used to edit and delete cookies.
/// </summary>
public class Cookies
{
private const string COOKIE_PASSWORD = "This cookie is very encrypted!!!";
private const int IV_SIZE = 16;
private HttpRequest _request;
private HttpResponse _response;
private Cookies()
{
// Use the other constructor.
}
public Cookies(HttpRequest request, HttpResponse response)
{
_request = request;
_response = response;
}
/// <summary>
/// Deletes a cookie.
/// </summary>
/// <param name="cookieToDelete"></param>
public void Delete(string cookieToDelete)
{
if (_request.Cookies[cookieToDelete] != null)
{
_response.Cookies.Remove(cookieToDelete);
HttpCookie myCookie = new HttpCookie(cookieToDelete);
myCookie.Expires = DateTime.Now.AddDays(-2d);
_response.Cookies.Add(myCookie);
}
return;
}
/// <summary>
/// Sets the value of a cookie.
/// </summary>
/// <param name="cookieName"></param>
/// <param name="cookieValue"></param>
public void Set(string cookieName, string cookieValue)
{
Set(cookieName, cookieValue, DateTime.Now.AddMonths(1));
return;
}
/// <summary>
/// Sets the value of a cookie.
/// </summary>
/// <param name="cookieName"></param>
/// <param name="cookieValue"></param>
public void Set(string cookieName, string cookieValue, DateTime expireTime)
{
HttpCookie newCookie;
newCookie = _response.Cookies[cookieName];
if (newCookie == null)
{
newCookie = new HttpCookie(cookieName, cookieValue);
newCookie.Expires = expireTime;
_response.Cookies.Add(newCookie);
}
else
{
newCookie.Value = cookieValue;
newCookie.Expires = DateTime.Now.AddMonths(1);
}
return;
}
/// <summary>
/// Gets the value of a cookie.
/// </summary>
/// <param name="cookieName"></param>
/// <returns></returns>
public string Get(string cookieName)
{
if (_request.Cookies[cookieName] != null)
{
return _request.Cookies[cookieName].Value;
}
return string.Empty;
}
/// <summary>
/// Generate a random IV.
/// </summary>
/// <returns></returns>
private static byte[] IV()
{
byte[] data = new byte[IV_SIZE];
System.Security.Cryptography.RandomNumberGenerator rnd = System.Security.Cryptography.RandomNumberGenerator.Create();
rnd.GetBytes(data);
return data;
}
/// <summary>
/// Extracts the IV from a message.
/// </summary>
/// <param name="message"></param>
/// <returns></returns>
private static byte[] IV(ref byte[] message)
{
byte[] returnValue = new byte[IV_SIZE];
byte[] newMessage = new byte[message.Length - IV_SIZE];
Array.Copy(message, returnValue, IV_SIZE);
Array.Copy(message, IV_SIZE, newMessage, 0, newMessage.Length);
message = newMessage;
return returnValue;
}
/// <summary>
/// Gets the value of a cookie and decrypts it.
/// </summary>
/// <param name="cookieName"></param>
/// <returns></returns>
public string GetEncrypted(string cookieName)
{
string cookieValue;
byte[] iv;
byte[] encrypted;
cookieValue = Get(cookieName);
if (!String.IsNullOrEmpty(cookieValue))
{
encrypted = System.Convert.FromBase64String(cookieValue);
iv = IV(ref encrypted);
// Create a new instance of the AesManaged
// class. This generates a new key and initialization
// vector (IV).
// Decrypt the bytes to a string.
cookieValue = DecryptStringFromBytes_Aes(encrypted, Key(), iv);
}
return cookieValue;
}
/// <summary>
/// Sets the value of a cookie. Encrypt it so the client can't mess with it.
/// </summary>
/// <param name="cookieName"></param>
/// <param name="cookieValue"></param>
/// <param name="expireTime"></param>
public void SetEncrypted(string cookieName, string cookieValue, DateTime expireTime)
{
string encryptedValue;
byte[] iv;
byte[] encrypted;
byte[] encryptedWithIV;
// Encrypt the string to an array of bytes.
iv = IV();
encrypted = EncryptStringToBytes_Aes(cookieValue, Key(), iv);
encryptedWithIV = new byte[iv.Length + encrypted.Length];
Array.Copy(iv, encryptedWithIV, iv.Length);
Array.Copy(encrypted, 0, encryptedWithIV, iv.Length, encrypted.Length);
encryptedValue = System.Convert.ToBase64String(encryptedWithIV);
Set(cookieName, encryptedValue, expireTime);
return;
}
private static byte[] EncryptStringToBytes_Aes(string plainText, byte[] key, byte[] iv)
{
byte[] encrypted;
// Create an AesManaged object
// with the specified key and IV.
using (AesManaged aesAlg = new AesManaged())
{
aesAlg.Key = key;
aesAlg.IV = iv;
// Create a decrytor to perform the stream transform.
ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for encryption.
using (MemoryStream msEncrypt = new MemoryStream())
{
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
{
//Write all data to the stream.
swEncrypt.Write(plainText);
}
encrypted = msEncrypt.ToArray();
}
}
}
// Return the encrypted bytes from the memory stream.
return encrypted;
}
private static byte[] Key()
{
return System.Text.ASCIIEncoding.ASCII.GetBytes(COOKIE_PASSWORD);
}
private static string DecryptStringFromBytes_Aes(byte[] cipherText, byte[] key, byte[] iv)
{
// Declare the string used to hold
// the decrypted text.
string plaintext = null;
// Create an AesManaged object
// with the specified key and IV.
using (AesManaged aesAlg = new AesManaged())
{
aesAlg.Key = key;
aesAlg.IV = iv;
// Create a decrytor to perform the stream transform.
ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for decryption.
using (MemoryStream msDecrypt = new MemoryStream(cipherText))
{
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
{
// Read the decrypted bytes from the decrypting stream
// and place them in a string.
plaintext = srDecrypt.ReadToEnd();
}
}
}
}
return plaintext;
}
}
}
答案 1 :(得分：0)
如果您使用的是Asp.Net Identity，则必须添加以下内容：
using System.Web.Security;
然后你就可以使用
了User.Identity.GetUserId()