CS1061 'HttpClient' does not contain a definition for 'PostAsJsonAsync' For asp.net core project

[hanslai]

Not sure if the is the right place to post this issue.

When try to following the Doc for "Integration Testing" example https://github.com/aspnet/Docs/tree/master/aspnetcore/mvc/controllers/testing/sample, for a pure asp.net core project, I got the following error.

CS1061 'HttpClient' does not contain a definition for 'PostAsJsonAsync'

Here are the nudge package was including.

<PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.3" />
  <PackageReference Include="Microsoft.AspNetCore.TestHost" Version="1.1.2" />
  <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.0.0" />
  <PackageReference Include="System.Net.Http" Version="4.3.2" />
  <PackageReference Include="xunit" Version="2.2.0" />
  <PackageReference Include="xunit.runner.visualstudio" Version="2.2.0" />

I have to add the package below to make it to work.
<PackageReference Include="WinInsider.System.Net.Http.Formatting" Version="1.0.5" />

But this does not seem right because the "TestingControllersSample" does not need to include it.

Is this a packing versioning problem? The "TestingControllersSample" is using "System.Net.Http Version"4.1.1"

Thanks

[Rick-Anderson]

I'm guessing the sample is missing a using statement.
WinInsider.System.Net.Http.Formatting is not an ASP.NET Core assembly.
We'll investigate, thanks for the report.

[hanslai]

@Rick-Anderson I am not sure if it is because of a missing using statement. I believe it is something else, below are the using statements

using Newtonsoft.Json;
using System.Linq;
using System.Collections.Generic;
using System.Net.Http;
using System.Threading.Tasks;
using Xunit;
using System.Net;

[hanslai]

@Rick-Anderson I just read this Where is PostAsJsonAsync method in ASP.NET Core?
on stackoverflow, and realized PostAsJsonAsync is not part of the aspnet.core.

So, I call end up unreference WinInsider.System.Net.Http.Formatting, but calling JsonConvert.SerializeObject(); first then call PostAsync instead.
But I still don't understand how the example https://github.com/aspnet/Docs/blob/master/aspnetcore/mvc/controllers/testing/sample/TestingControllersSample/tests/TestingControllersSample.Tests/IntegrationTests/ApiIdeasControllerTests.cs works by calling PostAsJsonAsync

My problem is solved, but I am not sure if I should close this issue, so please close it if you see fit.

Thanks

[Rick-Anderson]

@danroth27

I still don't understand how the example https://github.com/aspnet/Docs/blob/master/aspnetcore/mvc/controllers/testing/sample/TestingControllersSample/tests/TestingControllersSample.Tests/IntegrationTests/ApiIdeasControllerTests.cs works by calling PostAsJsonAsync

[danroth27]

In this case the sample includes its own implementation of PostAsJsonAsync:

https://github.com/aspnet/Docs/blob/master/aspnetcore/mvc/controllers/testing/sample/TestingControllersSample/tests/TestingControllersSample.Tests/IntegrationTests/HttpClientExtensions.cs

[SofiaSanabria]

I'm new here, I was pretty confused following that tutorial (Call a Web API From a .NET Client (C#))
I wrote this solution based on @Rick-Anderson comments, I hope this help.

using System.Web.Script.Serialization;
.
.
.
static async Task CreateProductAsync(Product product)
{
JavaScriptSerializer jss = new JavaScriptSerializer();
var myContent = jss.Serialize(product);
var httpContent = new StringContent(myContent, Encoding.UTF8, "application/json");
HttpResponseMessage response = await client.PostAsync("api/products", httpContent);
response.EnsureSuccessStatusCode();

        //return URI of the create resource.
        return response.Headers.Location;
    }

[optimum88]

Hi!
Just install Microsoft.AspNet.WebApi.Client nuget package

[sfshakil]

Hi!
Just install Microsoft.AspNet.WebApi.Client nuget package

correct answer.thanks