使用 POST 方法将 HttpWebRequest 转换为 HttpClient

Question

I try to convert HttpWebRequest to HttpClient but without success. Can anybody help me?

It is my simple code with HttpWebRequest:

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

I think you can convert you HttpWebRequest based code to HttpClient based like this:

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();

Remarks:

1. Instead of writing the Request's Stream manually you can use the ByteArrayContent abstraction for this. ( Related SO topic )
2. In order to set the cookie(s) manually you have to turn-off the default behaviour. You can do this via the HttpClientHandler's UseCookies . ( Related SO topic )
3. To set the headers manually you can use the HttpClient's DefaultRequestHeaders ( Related SO topic )
4. The counterpart of GetResponse is the SendAsync
5. Instead of reading the Response's Stream manually you can use the HttpContent's ReadAsStringAsync ( Related SO topic )

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UPDATE : Include OP's amended code

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

So, instead of ByteArrayContent StringContent is being used.