.Net 中单例内的对象

Question

举一个真实的例子。这是下面的类：

public class HttpClientWrapper : IHttpClientWrapper
{
    private static readonly ILogger Logger = LogManager.GetCurrentClassLogger();
    private readonly IStatsDPublisher _statsDPublisher;
    private readonly HttpClient _client;

    public HttpClientWrapper(IStatsDPublisher statsDPublisher, string baseAddress)
    {
        _statsDPublisher = statsDPublisher;
        _client = new HttpClient();


        _client.BaseAddress = new Uri(baseAddress);
        ServicePointManager.FindServicePoint(_client.BaseAddress).ConnectionLeaseTimeout = (int)TimeSpan.FromSeconds(60).TotalMilliseconds;
    }

    public async Task PostAsync<T>(string resource, T content)
    {
        var stringContent = new StringContent(JsonConvert.SerializeObject(content), Encoding.UTF8,"application/json");

        var name = typeof(T);

        using (var timer = _statsDPublisher.StartTimer($"HttpClient.{name.Name}.Post"))
        {
            try
            {
                await _client.PostAsync(resource, stringContent).ContinueWith(
                    (postTask) =>
                    {
                        postTask.Result.EnsureSuccessStatusCode();
                    });

                timer.StatName = $"{timer.StatName}.Success";
            }
            catch (Exception ex)
            {
                timer.StatName = $"{timer.StatName}.Failure";
                Logger.ExtendedException(ex, "Failed to Post.", new {Url = resource, Content = content});
                throw;
            }
        }
    }

    public async Task PutAsync<T>(string resource, T content)
    {
        var stringContent = new StringContent(JsonConvert.SerializeObject(content), Encoding.UTF8,
            "application/json");

        var name = typeof(T);

        using (var timer = _statsDPublisher.StartTimer($"HttpClient.{name.Name}.Put"))
        {
            try
            {
                await _client.PutAsync(resource, stringContent).ContinueWith(
                   (postTask) =>
                   {
                       postTask.Result.EnsureSuccessStatusCode();
                   });

                timer.StatName = $"{timer.StatName}.Success";
            }
            catch (Exception ex)
            {
                timer.StatName = $"{timer.StatName}.Failure";
                Logger.ExtendedException(ex, "Failed to Put.", new { Url = resource, Content = content });
                throw;
            }
         }
    }

} }

在 IoC 中，我们执行以下操作：

 Bind<IHttpClientWrapper>()
                .To<HttpClientWrapper>()
                .InSingletonScope()

所以现在是一个单例。我应该假设每次我们调用 HttpClientWrapper 时，我们是在处理同一个 HttpClient 实例，还是每次我们创建一个新实例？我相信每次访问 HttpClientWrapper 时，尽管是单例，您都会创建一个新的 HttpClient 实例。可以请教吗？

谢谢

Answer 1

单例意味着您在整个应用程序中只有一个类的单个实例。您根本无法创建该类的另一个实例。并且在你的单例中使用对象总是会返回相同的实例。 但是，您仍然可以在单例之外创建其他类的新实例。 所以答案显然是“不”。

希望对您有所帮助。