退出时，做了如下操作：

• (void)deleteCredient
  {

  //1、 NSDictionary *credentialsDict = [[NSURLCredentialStorage sharedCredentialStorage] allCredentials]; if ([credentialsDict count] > 0) { // the credentialsDict has NSURLProtectionSpace objs as keys and dicts of userName => NSURLCredential NSEnumerator *protectionSpaceEnumerator = [credentialsDict keyEnumerator]; id urlProtectionSpace; // iterate over all NSURLProtectionSpaces while (urlProtectionSpace = [protectionSpaceEnumerator nextObject]) { NSEnumerator *userNameEnumerator = [[credentialsDict objectForKey:urlProtectionSpace] keyEnumerator]; id userName; // iterate over all usernames for this protectionspace, which are the keys for the actual NSURLCredentials while (userName = [userNameEnumerator nextObject]) { NSURLCredential *cred = [[credentialsDict objectForKey:urlProtectionSpace] objectForKey:userName]; [[NSURLCredentialStorage sharedCredentialStorage] removeCredential:cred forProtectionSpace:urlProtectionSpace]; } } } //2、 NSURLCache *sharedCache = [NSURLCache sharedURLCache]; [sharedCache removeAllCachedResponses]; //3、 NSHTTPCookieStorage *cookieStorage = [NSHTTPCookieStorage sharedHTTPCookieStorage]; NSArray *cookies = [cookieStorage cookies]; for (NSHTTPCookie *cookie in cookies) { [cookieStorage deleteCookie:cookie]; NSLog(@"deleted cookie"); } [[NSUserDefaults standardUserDefaults]synchronize];

  }
  再次登陆时，先获取到当前的登陆账号和密码，account,passwd并缓存到本地，
  所有的请求接口都被封装在如下方法中，采用的是NTLM认证:

• (void)getWithURL:(NSString)url params:(NSDictionary)params success:(void (^)(id))success failure:(void (^)(NSError *))failure
  {

  AFHTTPRequestOperationManager *mgr = [AFHTTPRequestOperationManager manager]; NSString *account = [ZYFUserDefaults objectForKey:ZYFAccountKey]; NSString *passwd = [ZYFUserDefaults objectForKey:ZYFPwdKey]; NSURLCredential *credential = [NSURLCredential credentialWithUser:[@"XXXXXX\\" stringByAppendingString:account] password:passwd persistence:NSURLCredentialPersistenceForSession]; mgr.credential = credential; [mgr GET:url parameters:params success:^(AFHTTPRequestOperation *operation, id responseObject) { if (success) { success(responseObject); } } failure:^(AFHTTPRequestOperation *operation, NSError *error) { if (failure) { failure(error); } }];

  }