asp.net core WebApi 返回 HttpResponseMessage

ASP.NET WebApi 2 中的示例代码：

[Route("values/{id}")] public async Task<HttpResponseMessage> Get(string id) { var response = Request.CreateResponse(HttpStatusCode.OK); var accept = Request.Headers.Accept; var result = await _valuesService.Get(id); if (accept.Any(x => x.MediaType == "text/html")) { response.Content = new StringContent(result, Encoding.UTF8, "text/html"); } else { response.Content = new StringContent(result, Encoding.UTF8, "text/plain"); } return response; }

ASP.NET Core WebApi 中的示例代码：

[Route("values/{id}")] public async Task Get(string id) { var accept = Request.GetTypedHeaders().Accept; var result = await _valuesService.Get(id); var data = Encoding.UTF8.GetBytes(result); if (accept.Any(x => x.MediaType == "text/html")) { Response.ContentType = "text/html"; } else { Response.ContentType = "text/plain"; } await Response.Body.WriteAsync(data, 0, data.Length); }

可以看到，改变还是很大的，主要是两方面：

没有了 Request.CreateResponse，获取 Accept 需要通过 Request.GetTypedHeaders()。
没有返回值，而是直接通过数据流的方式写入到 Response.Body 中。