使用 POST 方法将 HttpWebRequest 转换为 HttpClient

Question

我尝试将 HttpWebRequest 转换为 HttpClient 但没有成功。 有人可以帮帮我吗？

这是我使用 HttpWebRequest 的简单代码：

string url = "https://www.somesite.com/Service";
string postData = "text to send";
var data = Encoding.ASCII.GetBytes(postData);
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
request.Method = "POST";
request.Proxy = null;
request.AllowAutoRedirect = false;
request.UserAgent = "Mozilla/5.0";
request.ContentType = "text/x-gwt-rpc; charset=UTF-8";
request.Headers.Add("Cookie", SetCookie);//get it after login
using (var stream = request.GetRequestStream())
{
stream.Write(data, 0, data.Length);
}
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
StreamReader reader = new StreamReader(response.GetResponseStream()); 
string responseText = reader.ReadToEnd();

Answer 1

我认为您可以将基于 HttpWebRequest 的代码转换为基于 HttpClient 的代码，如下所示：

string url = "https://www.somesite.com/Service";
string postData = "text to send";
var data = Encoding.ASCII.GetBytes(postData);
var content = new ByteArrayContent(data);

using var httpHandler = new HttpClientHandler { UseCookies =  false, AllowAutoRedirect = false };
using var client = new HttpClient(httpHandler);
client.DefaultRequestHeaders.Add("UserAgent","Mozilla/5.0");
client.DefaultRequestHeaders.Add("ContentType", "text/x-gwt-rpc; charset=UTF-8");
client.DefaultRequestHeaders.Add("Cookie", SetCookie);

using var requestMessage = new HttpRequestMessage(HttpMethod.Post, url) { Content = content };

var response = await client.SendAsync(requestMessage);
var responseText = await response.Content.ReadAsStringAsync();

备注：

1. 您可以使用ByteArrayContent 抽象来代替手动编写请求的流。 (Related SO topic)
2. 要手动设置 cookie，您必须关闭默认行为。您可以通过HttpClientHandler's UseCookies 执行此操作。 (Related SO topic)
3. 要手动设置标题，您可以使用HttpClient's DefaultRequestHeaders (Related SO topic)
4. GetResponse 的对应物是SendAsync
5. 您可以使用HttpContent's ReadAsStringAsync (Related SO topic) 代替手动读取响应流

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更新：包括 OP 的修改代码

var content = new StringContent(postData, Encoding.UTF8, "text/x-gwt-rpc");

因此，使用 ByteArrayContent 而不是 StringContent。