HttpClient.SendAsync示例：基础连接已关闭：连接意外关闭

Question

我有一个带有以下控制器的asp.net core 2.0 Web应用程序（使用Kestrel运行）：

public IActionResult GetUpdateList(string apiCode, int softwareId, [FromBody] List<SoftwareFile> updateFiles)
{
    try
    {
        var stream = SoftwareUpdateFilesHandler.GetUpdateZipFileStream(updateFiles, softwareId);
        return File(stream.BaseStream, "application/octet-stream", "UpdateFile");
    }
    catch (System.Exception ex)
    {
        return NotFound(ex.ToString());
    }
}

以及我客户端上的代码：

public async static Task<byte[]> GetUpdateAsync(string apiCode, int softwareId, List<SoftwareFile> updatefiles)
{
    try
    {
        StringContent content = null;
        if (updatefiles != null && updatefiles.Count > 0)
        {
            content = new StringContent(Newtonsoft.Json.JsonConvert.SerializeObject(updatefiles));
            content.Headers.ContentType = System.Net.Http.Headers.MediaTypeHeaderValue.Parse("application/json");
        }
        string address = $"{baseAddress}GetUpdate?softwareId={softwareId}";
        HttpRequestMessage request = new HttpRequestMessage(new HttpMethod("POST"), address);
        request.Content = content;
        var response = await httpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead);
        var responseContent = await response.Content.ReadAsByteArrayAsync();
        return responseContent;
    }
    catch(Exception ex)
    {
        return null;
    }
}

但是，当代码到达httpClient.SendAsync时，代码将挂起，几秒钟后客户端应用程序崩溃，我得到了这个异常：The underlying connection was closed: The connection was closed unexpectedly

当我在本地测试代码时，所有这些工作都很好，但是当我发布代码并尝试调用GetUpdateList时，我得到了异常。

奇怪的是，我无法在catch块中处理异常。不知何故，catch块无法捕获此异常，我可以在应用程序崩溃时看到异常。