C# HttpClient Cookie验证解决方法

HttpClient httpClient = new HttpClient(url, null, true);
httpClient.PostingData.Add(key,value);//登录用户名
httpClient.PostingData.Add(key,value);//密码
string str = httpClient.GetString();

CookieCollection cookies = httpClient.Context.Cookies;//保存一个全局的cookie文件
FileStream fileStream = new FileStream("xxx.dat", FileMode.Create);
BinaryFormatter b = new BinaryFormatter();
b.Serialize(fileStream, cookies);
fileStream.Close();

FileStream fileStream = new FileStream("xxx.dat", FileMode.Open, FileAccess.Read, FileShare.Read);
BinaryFormatter b = new BinaryFormatter();
CookieCollection cookies = b.Deserialize(fileStream) as CookieCollection;
HttpClient httpClient = new HttpClient("url");//取值的url
httpClient.Context.Cookies = cookies;
string str = httpClient.GetString();