HttpClient PostAsync

作者：刘杰

链接：http://www.zhihu.com/question/28050747/answer/41181841

来源：知乎

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String result = ""; HttpResponseMessage response = new HttpResponseMessage(); HttpClient httpClient = new HttpClient(); //登陆页面网址 String urlLogin = "https://ids-swust.fayea.com/cas/login?service=https%3A%2F%2Fmatrix%2Edean%2Eswust%2Eedu%2Ecn%2FacadmicManager%2Findex%2Ecfm%3Fevent%3DstudentPortal%3ADEFAULT%5FEVENT";
//登陆成功页面（倒计时，未真正进入主页） String urlLogined = "https://matrix.dean.swust.edu.cn/acadmicManager/index.cfm?event=studentPortal:DEFAULT_EVENT/"; //主页,需加上从上一个网页获取的ticket String urlMainPage = "https://matrix.dean.swust.edu.cn/acadmicManager/index.cfm?event=studentPortal:DEFAULT_EVENT&ticket=";
//课表页面 String urlTable = "https://matrix.dean.swust.edu.cn/acadmicManager/index.cfm?event=studentPortal:courseTable"; //设置 httpClient.MaxResponseContentBufferSize = 256000; httpClient.DefaultRequestHeaders.Add("user-agent", "Mozilla/5.0 (Windows NT 6.1; WOW64)
AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.143 Safari/537.36"); //进入登录页面（这一步是不是必须的安？） response = await httpClient.GetAsync(new Uri(urlLogin)); //result = response.Content.ReadAsStringAsync().Result; //要post去的信息 List<KeyValuePair<String, String>>
paramList = new List<KeyValuePair<String, String>>(); paramList.Add(new KeyValuePair<string, string>("lt", "LT-F11BE3E7-DC17-B420-8430351ECF173F51")); paramList.Add(new KeyValuePair<string, string>("username", username)); paramList.Add(new KeyValuePair<string,
string>("password", password)); paramList.Add(new KeyValuePair<string, string>("service", urlLogined)); //post过去，得到倒计时的页面 response = await httpClient.PostAsync(new Uri(urlLogin), new FormUrlEncodedContent(paramList)); result = response.Content.ReadAsStringAsync().Result;
//把得到的ticket加上再get几次，因为有倒计时，只好循环get直到内容变化，证明成功进入主页为止 int length = 0; for (int i = 0; i<10; i++)// { response = await httpClient.GetAsync(new Uri(urlMainPage)+GetTicket(result));//urlAim + GetTicket(result) result = response.Content.ReadAsStringAsync().Result;
if (i == 0)//记录第一次得到的源码长度，肯定没有成功进入 length = result.Length; if (i > 0 && result.Length != length) break;//登陆成功 } //进入课表页面 response = await httpClient.GetAsync(new Uri(urlTable)); result = response.Content.ReadAsStringAsync().Result; httpClient.Dispose();