PostAsync方法返回一个HttpResponseMessage，它包含Islam StatusCode和StatusCode属性。如果你使用它们，你的代码将是这样的：

public void Main()
{
    //String filePath = @"your-path\test.json";
    String filepath = Dts.Variables["User::FileName"].Value.ToString();
    if (File.Exists(filepath))
    {
        try
        {
            // Read the JSON file
            string jsonData = File.ReadAllText(filepath);
            using (var client = new HttpClient())
            {
                client.BaseAddress = new Uri("https://your-url.com");
                var response = client.PostAsync("/url-path", new StringContent(jsonData, Encoding.UTF8, "application/json")).Result;
                if (response.IsSuccessStatusCode)
                {
                    Console.WriteLine(response.StatusCode.ToString());

                    var responseContent = response.Content.ReadAsStringAsync();
                }

            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error reading or parsing the JSON file: {ex.Message}");
        }
    }
    else
    {
        Console.WriteLine("The JSON file does not exist in the specified folder.");
    }
}
}

HttpClient.PostAsync方法返回HttpResponseMessage对象，其中包含StatusCode属性和其他有关响应的附加信息。
因此，您可以在执行后通过使用以下字符串示例将其作为“StatusCode（StatusCodeDescription）”获取：$"{(int)response.StatusCode} ({response.ReasonPhrase})"（输出如200 (OK)、500 (InternalServerError)等）：

public void Main()
{
    // ...
    using (var client = new HttpClient())
    {
        // ...
        var response = client.PostAsync(...).Result;
        // ...
        Console.WriteLine($"{(int)response.StatusCode} ({response.ReasonPhrase})"); 
        // ...
    }
}

但是，请求的执行也可能抛出HttpRequestException（最简单的例子是超时）。而且，如果你在try-block中声明了HttpClient和HttpResponseMessage，你就不能在catch-block中得到response信息。这就是为什么你应该在try-catch块中声明它：

public void Main()
{
    // ...
    var client = new HttpClient();
    var response = (HttpResponseMessage?)null;
    // ...
    try
    {
        // ...
        response = client.PostAsync(...).Result;
        // ...
        Console.WriteLine($"{(int)response.StatusCode} ({response.ReasonPhrase})");
    }
    catch (Exception ex)
    {
        // Here you have access to response object, but don't forget null-checks
        Console.WriteLine($"{(int?)response?.StatusCode} ({response?.ReasonPhrase})");
    }
}

此外，应该提到很多关于代码的东西，比如：

• 不要在方法内部声明HttpClient以避免开销（参见this question）;
• 不要在可等待的Task上使用.Result，以避免死锁（请参阅this question）;
• 别忘了把你的Task给我。代码responseContent = response.Content.ReadAsStringAsync()中的一行代码将Task<string>对象存储在responseContent变量中，而不是像您期望的那样纯string。你应该await这个调用来获取字符串。

假设是这样，我建议您只声明和初始化HttpClient一次，在方法之外的某个地方，然后重用它。另外，将方法标记为async，以便能够等待HttpClient调用。通过这种方式，您可以获得正确的请求调用，响应处理和记录响应的能力。简单的例子：

private static readonly HttpClient _client = new() { BaseAddress = new Uri("SomeBaseUri") };

public static async Task Main()
{
    // ...
    var response = (HttpResponseMessage?)null;
    var responseContent = string.Empty;
    // ...
    try
    {
        // ...
        response = await _client.PostAsync(...);
        responseContent = await response.Content.ReadAsStringAsync();
        // ...
        Console.WriteLine($"Request executed with status: {(int)response.StatusCode} ({response.ReasonPhrase}). " +
                          $"Response body: {responseContent}");
    }
    catch (Exception ex)
    {
        Console.WriteLine($"Request failed with status: {(int?)response?.StatusCode} ({response?.ReasonPhrase}). " + 
                          $"Error: {ex.Message}");
    }

    // If job with HttpClient done - don't forget to dispose it manually:
    _client.Dispose();
}