asp.net-mvc - 在 MVC 6 中将 HTTP 响应传递给客户端

Question

我是 Web API 和 HTTP 的新手。

我正在使用 MVC 6(测试版)。我有一个代理服务(Web API)，它有一个 POST 方法来从另一个返回 XML 内容的服务获取响应。客户端不能直接调用服务，需要返回响应内容给客户端。

// In my proxy service
public HttpResponseMessage Post(String content) 
{
    using ( HttpClient client = new HttpClient() ) {

        .......

        HttpResponseMessage response = client.PostAsync(uri, content).Result;

        // I get everything I need in the "response".

        // How to return the response or it body to the client.
        // return response;
    }
}

我需要将“响应”返回给客户端，无需更改或更改最少。我试过“返回响应”，或创建一个新的 HttpResponseMessage，但我只得到类似的东西

{"Headers":[{"Key":"Content-Type","Value":["text/xml"]}]} 

在体内。

那么有没有一种简单的方法可以将响应传回给客户端呢？谢谢。

Answer 1

ASP.NET 团队目前正在开发一种“代理中间件”，它可以满足您的需求:https://github.com/aspnet/Proxy

这是它在内部的工作方式:

public async Task Invoke(HttpContext context)
{
    var requestMessage = new HttpRequestMessage();
    if (string.Equals(context.Request.Method, "POST", StringComparison.OrdinalIgnoreCase))
    {
        var streamContent = new StreamContent(context.Request.Body);
        requestMessage.Content = streamContent;
    }

    // Copy the request headers
    foreach (var header in context.Request.Headers)
    {
        if (!requestMessage.Headers.TryAddWithoutValidation(header.Key, header.Value) && requestMessage.Content != null)
        {
            requestMessage.Content?.Headers.TryAddWithoutValidation(header.Key, header.Value);
        }
    }

    requestMessage.Headers.Host = _options.Host + ":" + _options.Port;
    var uriString = $"{_options.Scheme}://{_options.Host}:{_options.Port}{context.Request.PathBase}{context.Request.Path}{context.Request.QueryString}";
    requestMessage.RequestUri = new Uri(uriString);
    requestMessage.Method = new HttpMethod(context.Request.Method);
    using (var responseMessage = await _httpClient.SendAsync(requestMessage, HttpCompletionOption.ResponseHeadersRead, context.RequestAborted))
    {
        context.Response.StatusCode = (int)responseMessage.StatusCode;
        foreach (var header in responseMessage.Headers)
        {
            context.Response.Headers.SetValues(header.Key, header.Value.ToArray());
        }

        foreach (var header in responseMessage.Content.Headers)
        {
            context.Response.Headers.SetValues(header.Key, header.Value.ToArray());
        }

        // SendAsync removes chunking from the response. This removes the header so it doesn't expect a chunked response.
        context.Response.Headers.Remove("transfer-encoding");
        await responseMessage.Content.CopyToAsync(context.Response.Body);
    }
}

https://github.com/aspnet/Proxy/blob/dev/src/Microsoft.AspNet.Proxy/ProxyMiddleware.cs