在 .net 4.5 中尝试使用 HttpClient 使 cookie 无法响应
我有以下代码可以成功运行。我不知道如何从响应中获取 cookie。我的目标是我希望能够在请求中设置 cookie 并从响应中获取 cookie。想法？
private async Task<string> Login(string username, string password)
{
try
{
string url = "http://app.agelessemail.com/account/login/";
Uri address = new Uri(url);
var postData = new List<KeyValuePair<string, string>>
{
new KeyValuePair<string, string>("username", username),
new KeyValuePair<string, string>("password ", password)
};
HttpContent content = new FormUrlEncodedContent(postData);
var cookieJar = new CookieContainer();
var handler = new HttpClientHandler
{
CookieContainer = cookieJar,
UseCookies = true,
UseDefaultCredentials = false
};
var client = new HttpClient(handler)
{
BaseAddress = address
};
HttpResponseMessage response = await client.PostAsync(url,content);
response.EnsureSuccessStatusCode();
string body = await response.Content.ReadAsStringAsync();
return body;
}
catch (Exception e)
{
return e.ToString();
}
}
这是完整的答案：
HttpResponseMessage response = await client.PostAsync(url,content);
response.EnsureSuccessStatusCode();
Uri uri = new Uri(UrlBase);
var responseCookies = cookieJar.GetCookies(uri);
foreach (Cookie cookie in responseCookies)
{
string cookieName = cookie.Name;
string cookieValue = cookie.Value;
}
要将 cookie 添加到请求，请在请求之前使用 CookieContainer.Add(uri, cookie) 填充 cookie 容器。发出请求后，cookie 容器将自动填充来自响应的所有 cookie。然后，您可以调用 GetCookies() 来检索它们。
CookieContainer cookies = new CookieContainer();
HttpClientHandler handler = new HttpClientHandler();
handler.CookieContainer = cookies;
HttpClient client = new HttpClient(handler);
HttpResponseMessage response = client.GetAsync("http://google.com").Result;
Uri uri = new Uri("http://google.com");
IEnumerable<Cookie> responseCookies = cookies.GetCookies(uri).Cast<Cookie>();
foreach (Cookie cookie in responseCookies)
Console.WriteLine(cookie.Name + ": " + cookie.Value);
Console.ReadLine();
如果您无权访问 HttpClient 并且无法注入 CookieContainer，则可以使用另一种方法。这适用于 .NET Core 2.2：
private string GetCookie(HttpResponseMessage message)
{
message.Headers.TryGetValues("Set-Cookie", out var setCookie);
var setCookieString = setCookie.Single();
var cookieTokens = setCookieString.Split(';');
var firstCookie = cookieTokens.FirstOrDefault();
var keyValueTokens = firstCookie.Split('=');
var valueString = keyValueTokens[1];
var cookieValue = HttpUtility.UrlDecode(valueString);
return cookieValue;
}
var setCookieString = setCookie.Single();，因为 setCookie 很可能有多个值，从而导致抛出异常。我最终添加了一个参数 string cookieName，然后使用了 setCookie.Single(x => x.StartsWith(cookieName));。这仍然假设请求的 cookie 存在。
Set-Cookie 标头确实有多个值，它们用分号 (;) 分隔，但通常应该只有一个 Set-Cookie 标头
您可以使用给定的 URL 轻松获取 cookie 值。
private async Task<string> GetCookieValue(string url, string cookieName)
{
var cookieContainer = new CookieContainer();
var uri = new Uri(url);
using (var httpClientHandler = new HttpClientHandler
{
CookieContainer = cookieContainer
})
{
using (var httpClient = new HttpClient(httpClientHandler))
{
await httpClient.GetAsync(uri);
var cookie = cookieContainer.GetCookies(uri).Cast<Cookie>().FirstOrDefault(x => x.Name == cookieName);
return cookie?.Value;
}
}
}
并非在所有情况下都可以将 httpClientHandler 添加到 httpClient。例如，当您使用集成测试 testServer.CreateClient() 或从 IHttpClientFactory 注入 httpClient 时。所以，我只是从标题中读取值。
public static List<Cookie> GetCookies(this HttpResponseMessage message)
{
message.Headers.TryGetValues("Set-Cookie", out var cookiesHeader);
var cookies = cookiesHeader.Select(cookieString => CreateCookie(cookieString)).ToList();
return cookies;
}
private static Cookie CreateCookie(string cookieString)
{
var properties = cookieString.Split(';', StringSplitOptions.TrimEntries);
var name = properties[0].Split("=")[0];
var value = properties[0].Split("=")[1];
var path = properties[2].Replace("path=", "");
var cookie = new Cookie(name, value, path)
{
Secure = properties.Contains("secure"),
HttpOnly = properties.Contains("httponly"),
Expires = DateTime.Parse(properties[1].Replace("expires=", ""))
};
return cookie;
}
CreateCookie 方法可能会被修改以完全匹配您的 cookie 属性。
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httpclient是从 httpclient 工厂构建的，是否可以以相同的方式获取 cookie？即添加到services.AddHttpClient的builder方法