C#：带有 POST 参数的 HttpClient

Question

我使用下面的代码向服务器发送 POST 请求：

string url = "http://myserver/method?param1=1&param2=2"    
HttpClientHandler handler = new HttpClientHandler();
HttpClient httpClient = new HttpClient(handler);
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, url);
HttpResponseMessage response = await httpClient.SendAsync(request);

我无权访问服务器进行调试，但我想知道，此请求是作为 POST 还是 GET 发送的？

如果是 GET，如何更改我的代码以将 param1 和 param2 作为 POST 数据（不在 URL 中）发送？

Answer 1

更简洁的替代方法是使用Dictionary来处理参数。 毕竟它们是键值对。

private static readonly HttpClient httpclient;

static MyClassName()
{
    // HttpClient is intended to be instantiated once and re-used throughout the life of an application. 
    // Instantiating an HttpClient class for every request will exhaust the number of sockets available under heavy loads. 
    // This will result in SocketException errors.
    // https://docs.microsoft.com/en-us/dotnet/api/system.net.http.httpclient?view=netframework-4.7.1
    httpclient = new HttpClient();    
} 

var url = "http://myserver/method";
var parameters = new Dictionary<string, string> { { "param1", "1" }, { "param2", "2" } };
var encodedContent = new FormUrlEncodedContent (parameters);

var response = await httpclient.PostAsync (url, encodedContent).ConfigureAwait (false);
if (response.StatusCode == HttpStatusCode.OK) {
    // Do something with response. Example get content:
    // var responseContent = await response.Content.ReadAsStringAsync ().ConfigureAwait (false);
}

也不要忘记Dispose() httpclient，如果你不使用关键字using

如Microsoft 文档中HttpClient 类的备注部分所述，HttpClient 应实例化一次并重复使用。

编辑：

您可能需要查看response.EnsureSuccessStatusCode(); 而不是if (response.StatusCode == HttpStatusCode.OK) 。

您可能希望保留您的 httpclient 并且不要Dispose()它。 请参阅： HttpClient 和 HttpClientHandler 是否必须被处置？

编辑：

不要担心在 .NET Core 中使用 .ConfigureAwait(false)。 有关更多详细信息，请查看https://blog.stephencleary.com/2017/03/aspnetcore-synchronization-context.html

Answer 2

正如本所说，您正在发布您的请求（在您的代码中指定 HttpMethod.Post ）

您的 url 中包含的查询字符串 (get) 参数可能不会做任何事情。

尝试这个：

string url = "http://myserver/method";    
string content = "param1=1&param2=2";
HttpClientHandler handler = new HttpClientHandler();
HttpClient httpClient = new HttpClient(handler);
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, url);
HttpResponseMessage response = await httpClient.SendAsync(request,content);

哈，

博瓦科