使用 HttpClient 时如何解决 302 错误？答案

【问题标题】：How do I resolve 302 Error when using HttpClient?使用 HttpClient 时如何解决 302 错误？
【发布时间】：2019-01-24 21:55:11
【问题描述】：

我创建了一个自定义 DNN 模块，该模块使用 HTTPClient 将信息发送到外部 API。我的HttpClient方法如下：

public static async Task<string> CreatePayerResponse()
    {
        var credentials = GetCredentials();
        var objEventLog = new EventLogController();
        var gatewaySettings = new GatewaySetting_ProPay();
        SignupResult_ProPay result = new SignupResult_ProPay();
        using (HttpClient client = new HttpClient(new LoggingHandler(new HttpClientHandler())))
        {
            HttpRequestMessage request = new HttpRequestMessage();
            HttpResponseMessage response = new HttpResponseMessage();
            response.EnsureSuccessStatusCode();
            client.BaseAddress = new Uri("https://xmltestapi.propay.com/ProPayAPI/signup");
            client.DefaultRequestHeaders.Clear();
            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

            string responseBody;
            GatewaySetting_ProPay gatewaySetting = new GatewaySetting_ProPay();
            SignupRequest payerRequest = new SignupRequest();
            HttpContent content = new StringContent(payerRequest.ToString());
            try
            {
                request.Headers.Add("Authorization", credentials);
                request.Headers.Add("accept", "application/json");
                response = await client.PutAsync("https://xmltestapi.propay.com/ProPayAPI/signup", content);
                responseBody = await response.Content.ReadAsStringAsync();
                objEventLog.AddLog("Merchant Onboarding Request Sent", portalSettings, userId,
                    response.ToString(), EventLogController.EventLogType.ADMIN_ALERT);
                Console.WriteLine(responseBody);

            }
            catch (HttpRequestException ex)
            {
                result.Succeeded = false;
                result.Status = ex.Message;
                objEventLog.AddLog("Merchant Onboarding Error!", portalSettings, userId, response.ToString(),
                    EventLogController.EventLogType.ADMIN_ALERT);
                Console.WriteLine("\nException Caught!");
                Console.WriteLine("Message :{0} ", ex.Message);
            }

            return response.Content.ToString();
        }
    }
public static string GetCredentials()
    {
        GatewaySetting_ProPay gatewaySettings = new GatewaySetting_ProPay();
        var billerAccountId = "mycreds";
        var authToken = "mycreds";
        var encodedCredentials =
            Convert.ToBase64String(Encoding.Default.GetBytes(billerAccountId + ":" + authToken));
        var credentials = string.Format("Basic {0}", encodedCredentials);
        return credentials;
    }

当我将此方法连接到单击事件时，会收到 HTTP 302 响应，但不会向 API 发送任何内容。需要进行哪些修改才能确保正确传输？

更新我仍然收到以下回复：

Error code 302 was received from server response.

尽管实现了 AllowAutoRedirect 属性并将其设置为 true，但仍然如此。这是我编写的 LoggingHandler 类：

public LoggingHandler(HttpMessageHandler innerHandler) : base(innerHandler)
    {

    }
    protected async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken, HttpClientHandler handler)
    {
        Console.WriteLine("Request:");
        Console.WriteLine(request.ToString());
        if (request.Content != null)
        {
            Console.WriteLine(await request.Content.ReadAsStringAsync());
        }
        Console.WriteLine();
        handler.AllowAutoRedirect = true;
        HttpResponseMessage response = await base.SendAsync(request, cancellationToken);


        Console.WriteLine("Response:");
        Console.WriteLine(response.ToString());
        if (response.Content != null)
        {
            Console.WriteLine(await response.Content.ReadAsStringAsync());
        }
        Console.WriteLine();

        return response;
    }

这是实现 HttpClientHandler 和相关属性的正确方法吗？

【问题讨论】：

标签： c# dotnetnuke system.net

【解决方案1】：

确保 HttpClientHandler 实例的 AllowAutoRedirect 属性设置为 true 并被您的 HttpClient 使用。

【讨论】：

感谢您的回答。请查看我的更新并告知我是否有效地实施了此属性。非常感谢。

【解决方案2】：

在对 System.Net.Http 和相关命名空间实现跟踪日志后，日志显示连接被强制关闭。经过进一步研究，事实证明 .NET Framework 4.5 与更现代的传输层安全 (TLS) 版本不兼容。因此，必须放弃从我们的 DNN 应用程序调用 API 的方法，因为我们正在扩展的源代码目标是 .NET Framework 4.5 版。

【讨论】：