我如何使用JSON从Web.api返回的值

Question

如何使用JSON返回Web.api的值？

MVC控制器的代码：

try
{
    HttpClient cl = new HttpClient();
    cl.BaseAddress = new Uri("http://localhost:35936");
    cl.DefaultRequestHeaders.Add("ApiUser", "User");
    cl.DefaultRequestHeaders.Add("Password", "Password");
    cl.DefaultRequestHeaders.Add("MyVar", "1234");
    cl.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));               
    string json = JsonConvert.SerializeObject(testedVar);
    var sucSender = await cl.PostAsJsonAsync("api/sender/successtested", json);
    if (sucSender.IsSuccessStatusCode)
    {
       var newvar = JsonConvert.DeserializeObject<Tested>(sucSender.ToString());                 
    } 
}

web.api的代码：

string forReturn = "222444";
Tested forRetVar = new Tested
{
    test = forReturn
};
var test123 = JsonConvert.SerializeObject(forRetVar);
return  JsonConvert.SerializeObject(forRetVar);          

Answer 1

您必须修改如何发布和阅读响应。

从

修改帖子调用

var sucSender = await cl.PostAsJsonAsync("api/sender/successtested", json);

to

var sucSender = await cl.PostAsJsonAsync("api/sender/successtested", json).ConfigureAwait(false);

并修改从此操作的响应读取调用

var newvar = JsonConvert.DeserializeObject<Tested>(sucSender.ToString());

to

var newvar = await sucSender.Content.ReadAsAsync<Tested>();

这是基于我自己的测试样本的完整代码。我有一个位于http：//localhost/mytesttwo托管的Test2 API控制器，该控制器使用httpclient在内部称为http：//localhost/mytestapi的另一个API。为了使其简单，我一直保持Test2Controller获取方法同步，而不是将其转换为异步等待模式。两个WebAPI应用程序均在IIS中配置为具有匿名身份验证。

using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;
using System.Web.Http;
namespace MyTestTwo.Controllers
{
    public class Test2Controller : ApiController
    {
        public IHttpActionResult Get()
        {
            var employeesTask = GetEmp();
            employeesTask.Wait();
            var employees = employeesTask.Result;
            return Ok(employees);
        }
        private async Task<IEnumerable<string>> GetEmp()
        {
            IEnumerable<string> response = new List<string>();
            var cl = new HttpClient();
            cl.BaseAddress = new Uri("http://localhost/MyTestApp/");
            cl.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
            var sucSender = await cl.PostAsJsonAsync("api/MyTest", "test").ConfigureAwait(false);
            if (sucSender.IsSuccessStatusCode)
            {
                response = await sucSender.Content.ReadAsAsync<IEnumerable<string>>();
            }
            return response;
        }
    }
}

请参阅此帖子从PostAsjSonAsync和httpclient.getAsync（...）中获取响应。