Question

我有以下代码：

public class HttpRequestsHandler
    {
        public static T HttpGetWithContent<T>(string requestUrl)
        {
            using (var handler = new WebRequestHandler())
            {
                handler.ServerCertificateValidationCallback = (sender, certificate, chain, errors) => true;

                using (var httpClient = new HttpClient(handler)
                {
                    BaseAddress = new Uri(requestUrl),
                    Timeout = Timeout.InfiniteTimeSpan
                })
                {
                    using (var response = httpClient.GetAsync(requestUrl).Result)
                    {
                        if (response.StatusCode != HttpStatusCode.OK && response.StatusCode != HttpStatusCode.Gone)
                        {
                            var errorMessage = $"HttpRequestTask: Request failed with status {response.StatusCode} for URL: {requestUrl}";
                            throw new HttpException(errorMessage, (int)response.StatusCode);
                        }
                        return response.Content.ReadAsAsync<T>().Result;
                    }
                }
            }
        }
        public static T HttpGetWithContentWrapper<T>(string requestUrl)
        {
            return HttpGetWithContent<T>(requestUrl);
        }
  }

现在我打电话的时候：

private void Button_Click(object sender, DoWorkEventArgs e)
    {
        var worker = new BackgroundWorker();
        worker.DoWork += (sender, args) =>
        {
            var url = UrlProvider.BuildRequestUrl();
            var date = HttpRequestsHandler.HttpGetWithContent<DateTime>(url);
            //More code...
        };
        worker.RunWorkerCompleted += (sender, args) =>
        {
           //more code...
        };
        worker.RunWorkerAsync();
    }

它就像一个魅力，但当我用一个包装器方法：

private void Button_Click(object sender, DoWorkEventArgs e)
    {
        var worker = new BackgroundWorker();
        worker.DoWork += (sender, args) =>
        {
            var url = UrlProvider.BuildRequestUrl();
            var date = HttpRequestsHandler.HttpGetWithContentWrapper<DateTime>(url); //fails here
            //More code...
        };
        worker.RunWorkerCompleted += (sender, args) =>
        {
           //more code...
        };
        worker.RunWorkerAsync();
    }

以错误结束＆＃34;不可访问的区域＆＃34;。

现在我想这与我的一次性模式有关;我不熟悉。根据我的理解，它用于应用程序中的非托管资源，因此对象只存在于使用＆＃39;。

我不明白的是它如何在fisrt部分返回一个值而不是在第二个部分...

感谢，

更新 - 我很抱歉，从操作代码到使其工作我粘贴错了，我将其更改为原始代码给了我麻烦，谢谢

Answer 1

尝试更改

public static T HttpGetWithContentWrapper<T>(string requestUrl)
{
    return HttpGetWithContent<T>(string requestUrl);
}

到

public static T HttpGetWithContentWrapper<T>(string requestUrl)
{
    return HttpGetWithContent<T>(requestUrl);
}

通过编写string requestUrl作为参数，您实际上是将空字符串传递给您的方法。也许这就是导致错误的原因（假设您的实际代码中存在此错误，而不仅仅是在示例中）。

从处理方法返回价值

1 个答案: