Question

我试图为批量请求编写中间件i .net core 2.0。到目前为止，我已经拆分了请求，将每个请求传递给控制器。控制器返回值，但由于某种原因，我解析到控制器的创建上下文的响应不断给我一个NullStream，所以我认为在我的设置中有一些我想念的东西。

代码如下所示：

var json = await streamHelper.StreamToJson(context.Request.Body);

var requests = JsonConvert.DeserializeObject<IEnumerable<RequestModel>>(json);

var responseBody = new List<ResponseModel>();

foreach (var request in requests)
{
    var newRequest = new HttpRequestFeature
    {
        Body = request.Body != null ? new MemoryStream(Encoding.ASCII.GetBytes(request.Body)) : null,
        Headers = context.Request.Headers,
        Method = request.Method,
        Path = request.RelativeUrl,
        PathBase = string.Empty,
        Protocol = context.Request.Protocol,
        Scheme = context.Request.Scheme,
        QueryString = context.Request.QueryString.Value
    };

    var newRespone = new HttpResponseFeature();
    var requestLifetimeFeature = new HttpRequestLifetimeFeature();

    var features = CreateDefaultFeatures(context.Features);
    features.Set<IHttpRequestFeature>(newRequest);
    features.Set<IHttpResponseFeature>(newRespone);
    features.Set<IHttpRequestLifetimeFeature>(requestLifetimeFeature);

    var innerContext = _factory.Create(features);
    await _next(innerContext);

    var responseJson = await streamHelper.StreamToJson(innerContext.Response.Body);

我不确定我在设置中缺少什么，因为innerContext.Response.Body没有设置。

我用于测试和被点击的端点之一就像这样

[Route("api/[controller]")]
public class ValuesController : Controller
{
    // GET api/values
    [HttpGet]
    public IEnumerable<string> Get()
    {
        return new string[] { "value1", "value2" };
    }
}

Answer 1

我发现了错误或两个错误，无法正常工作。

首先，我必须将newResponse更改为

var newRespone = new HttpResponseFeature{ Body = new MemoryStream() };

由于HttpResponseFeature在构造函数中将Body设置为Stream.Null。

当完成后，Body在尝试阅读时保持空字符串。这是通过将位置设置为零来修复的，如

innerContext.Response.Body.Position = 0;

对创建的上下文的响应不断给我NullStream

1 个答案: