public class BasicUsageModel : PageModel

{

    private readonly IHttpClientFactory _clientFactory;

    public IEnumerable<GitHubBranch> Branches { get; private set; }

    public bool GetBranchesError { get; private set; }

    public BasicUsageModel(IHttpClientFactory clientFactory)

    {

        _clientFactory = clientFactory;

    }

    public async Task OnGet()

    {

        var request = new HttpRequestMessage(HttpMethod.Get,

            "https://api.github.com/repos/aspnet/AspNetCore.Docs/branches");

        request.Headers.Add("Accept", "application/vnd.github.v3+json");

        request.Headers.Add("User-Agent", "HttpClientFactory-Sample");

        var client = _clientFactory.CreateClient();

        var response = await client.SendAsync(request);

        if (response.IsSuccessStatusCode)

        {

            var responseStream = await response.Content.ReadAsStreamAsync();

            Branches = await JsonSerializer.DeserializeAsync

                <IEnumerable<GitHubBranch>>(responseStream);

        }

        else

        {

            GetBranchesError = true;

            Branches = Array.Empty<GitHubBranch>();

        }

    }
仔细看没什么问题吧？

using var responseStream = await response.Content.ReadAsStreamAsync();

使用的时候没加using,导致并发连接数高一直没有释放，致使应用奔溃