如何在C＃中使用PostAsync设置多个标头？

Question

我有一些工作代码：

using (var client = new HttpClient())
{
HttpResponseMessage response;
response = client.PostAsync(Url, new StringContent(Request, Encoding.UTF8, header)).Result;
}

//以上工作适用于简单的标题，例如“application / json”

如果我想要多个标题，我该怎么办？ 例如添加“myKey”，“foo”对和“Accept”，“image / foo1”

如果我尝试在.Result行之前添加以下内容，则intellisense会抱怨（“标题”一词为红色，“无法解析符号'标题'”：

client.Headers.Add("myKey", "foo");
client.Headers.Add("Accept", "image/foo1");

Answer 1

您可以通过StringContent访问Headers属性：

var content = new StringContent(Request, Encoding.UTF8, header);
content.Headers.Add(...);

然后将StringContent传递给PostAsync调用：

response = client.PostAsync(Url, content).Result;

Answer 2

我停止使用Post / Get * Async方法支持SendAsync(...)方法和HttpRequestMessage Send Async是大哥，它可以让您获得您无法实现的全部灵活性。

using System.Net.Http;

var httpRequestMessage = new HttpRequestMessage();

httpRequestMessage.Method = httpMethod;
httpRequestMessage.RequestUri = new Uri(url);

httpRequestMessage.Headers
                  .UserAgent
                  .Add(new Headers.ProductInfoHeaderValue(
                                              _applicationAssembly.Name, 
                                              _applicationAssembly.Version.ToString()));

HttpContent httpContent = new StringContent(json, Encoding.UTF8, "application/json");
switch (httpMethod.Method)
{
    case "POST":
        httpRequestMessage.Content = httpContent;
        break;
}

var result = await httpClient.SendAsync(httpRequestMessage);
result.EnsureSuccessStatusCode();

Answer 3

你也可以使用

var client = new HttpClient();
client.DefaultRequestHeaders.TryAddWithoutValidation("headername","headervalue");

如果你只想在HttpClient类上设置一次标题。 以下是DefaultRequestHeaders.TryAddWithoutValidation的MSDN文档