Where is the PostAsJsonAsync method in ASP.NET Core?

Question

I was looking for the PostAsJsonAsync() extension method in ASP.NET Core. Based on this article, it\'s available in the Microsoft.AspNet.WebApi.Client

Answer 1

Just update your Nuget Packages into SDK .Net Core 2.1 or to the latest .Net Core SDK and it will be working.

Answer 2

The methodPostAsJsonAsync (along with other *Async methods of the HttpClient class) is indeed available out of the box - without using directives.

Your .csproj file should start with <Project Sdk="Microsoft.NET.Sdk.Web">, and contain the lines

<ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.App" />
</ItemGroup>

I believe this is a duplicate, and have given a more elaborated answer at https://stackoverflow.com/questions/37750451#58169080.

(The PackageReference is no longer needed in .NET Core 3.0.)

Answer 3

It comes as part of the library Microsoft.AspNet.WebApi.Client https://www.nuget.org/packages/Microsoft.AspNet.WebApi.Client/

Answer 4

You Can Use This Extension for use PostAsJsonAsync method in ASP.NET core

using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;
using Newtonsoft.Json;
public static class HttpClientExtensions
{
    public static Task<HttpResponseMessage> PostAsJsonAsync<T>(this HttpClient httpClient, string url, T data)
    {
        var dataAsString = JsonConvert.SerializeObject(data);
        var content = new StringContent(dataAsString);
        content.Headers.ContentType = new MediaTypeHeaderValue("application/json");

        return httpClient.PostAsync(url, content);
    }

    public static Task<HttpResponseMessage> PutAsJsonAsync<T>(this HttpClient httpClient, string url, T data)
    {
        var dataAsString = JsonConvert.SerializeObject(data);
        var content = new StringContent(dataAsString);
        content.Headers.ContentType = new MediaTypeHeaderValue("application/json");

        return httpClient.PutAsync(url, content);
    }

    public static async Task<T> ReadAsJsonAsync<T>(this HttpContent content)
    {
        var dataAsString = await content.ReadAsStringAsync().ConfigureAwait(false);

        return JsonConvert.DeserializeObject<T>(dataAsString);
    }
}

see: httpclient-extensions

Answer 5

make the extension method truly async:

public static async Task<HttpResponseMessage> PostAsJsonAsync<T>(
    this HttpClient httpClient, string url, T data)
{
    var dataAsString = JsonConvert.SerializeObject(data);
    var content = new StringContent(dataAsString);
    content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
    return await httpClient.PostAsync(url, content);
}

Answer 6

this is coming late but I think it may help someone down the line. So the *AsJsonAsync() methods are not part of the ASP.NET Core project. I created a package that gives you the functionality. You can get it on Nuget.

https://www.nuget.org/packages/AspNetCore.Http.Extensions

using AspNetCore.Http.Extensions;
...
HttpClient client = new HttpClient();
client.PostAsJsonAsync('url', payload);