反序列化时出错 Json .NET CORE 5 - Json异常：检测到不支持的可能对象循环

Question

基本上我在 .NET 5 上创建了一个 API 项目。我的想法是在 GitHub API 上获取一些存储库信息，然后在我的 [=38] 中取消一些信息=].请求成功但是，但是在将Json转换为object

时总是出现同样的错误

存储库控制器：

using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text.Json;
using System.Threading.Tasks;

[ApiController]
[Route("[controller]")]
public class RepositoriesController : ControllerBase
{
    private static readonly HttpClient client = new HttpClient();

    private readonly ILogger<RepositoriesController> _logger;

    public RepositoriesController(ILogger<RepositoriesController> logger)
    {
        _logger = logger;
    }

    [HttpGet]
    public IActionResult Get(string number)
    {
        return Ok(ProcessRepositories());
    }

    private static async Task ProcessRepositories()
    {
        client.DefaultRequestHeaders.Accept.Clear();
        client.DefaultRequestHeaders.Accept.Add(
            new MediaTypeWithQualityHeaderValue("application/vnd.github.v3+json"));
        client.DefaultRequestHeaders.Add("User-Agent", ".NET Foundation Repository Reporter");

        var streamTask = client.GetStreamAsync("https://api.github.com/orgs/dotnet/repos?sort=created&per_page=5&direction=desc");
        var repositories = await JsonSerializer.DeserializeAsync<List<Repository>>(await streamTask);
    }
}

类存储库：

 public class Repository
{
    public string full_name { get; set; }
    public string node_id { get; set; }
    //public string description { get; set; }
}

但总是在这部分：

        var repositories = await JsonSerializer.DeserializeAsync<List<Repository>>(await streamTask);

浏览器return这个错误：

JsonException: A possible object cycle was detected. This can either be due to a cycle or if the object depth is larger than the maximum allowed depth of 32. Consider using ReferenceHandler.Preserve on JsonSerializerOptions to support cycles.

我想了解为什么即使有两个与 json

同名的简单属性也会出现错误

GitHub Api 文档 https://docs.github.com/en/rest/reference/repos

用作请求 api 基础的文档： https://docs.microsoft.com/en-us/dotnet/csharp/tutorials/console-webapiclient#deserialize-the-json-result

Github返回Json（我隐藏了json的一些属性，因为有几个）

[
    {
        "id": 1296269,
        "node_id": "MDEwOlJlcG9zaXRvcnkxMjk2MjY5",
        "name": "Hello-World",
        "full_name": "octocat/Hello-World",
        [... several hidden properties for display purposes]
    }
]

提前致谢:)

Answer 1

我建议切换到 Newtonsoft.Json 来处理循环引用问题。

1.Install NewtonsoftJson 包。

Install-Package Microsoft.AspNetCore.Mvc.NewtonsoftJson

2.Add并在ConfigureServices中进行配置。

services.AddControllers().AddNewtonsoftJson(options=>
    options.SerializerSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore);

3.Use Json转换为反序列化。

client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(
    new MediaTypeWithQualityHeaderValue("application/vnd.github.v3+json"));
client.DefaultRequestHeaders.Add("User-Agent", ".NET Foundation Repository Reporter");

var streamTask = await client.GetStringAsync("https://api.github.com/orgs/dotnet/repos?sort=created&per_page=5&direction=desc");
var repositories = JsonConvert.DeserializeObject<List<Repository>>(streamTask);

反序列化时出错 Json .NET CORE 5 - Json异常：检测到不支持的可能对象循环

Error when deserialize Json .NET CORE 5 - JsonException: A possible object cycle was detected which is not supported

c#

json

deserialization

asp.net-core

asp.net-core-webapi