Question

我的网络API中有一个操作正在返回HttpResponseMessage：

public async Task<HttpResponseMessage> Create([FromBody] AType payload)
{
    if (payload == null)
    {
        throw new ArgumentNullException(nameof(payload));
    }

    await Task.Delay(1);

    var t = new T { Id = 0, Name = payload.tName, Guid = Guid.NewGuid() };

    var response = new MyResponse { T = t };

    var result = new HttpResponseMessage(HttpStatusCode.OK) { Content = new ObjectContent(typeof(MyResponse), response, new JsonMediaTypeFormatter { SerializerSettings = { NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore } }) };

    return result;
}

现在，我的问题是，如果发出请求且请求的Content-Type为application/xml，我应该使用xml formatter来设置回复的正文。

有没有办法使用泛型类，让框架根据请求的内容类型决定在运行时使用哪种格式化程序？

Answer 1

在请求中使用CreateResponse扩展方法，它将允许基于相关请求进行内容协商。如果要根据请求的内容类型强制内容类型，请从请求中获取内容类型并将其包含在create response overloads中。

public class MyApitController : ApiController {
    [HttpPost]
    public async Task<HttpResponseMessage> Create([FromBody] AType payload) {
        if (payload == null) {
            throw new ArgumentNullException(nameof(payload));
        }

        await Task.Delay(1);

        var t = new T { Id = 0, Name = payload.tName, Guid = Guid.NewGuid() };

        var response = new MyResponse { T = t };

        var contentType = Request.Content.Headers.ContentType;

        var result = Request.CreateResponse(HttpStatusCode.OK, response, contentType);

        return result;
    }

}

理想情况下，返回的类型应基于请求表明它要接受的内容。该框架确实允许该主题具有灵活性。

选中此处以获取更多信息Content Negotiation in ASP.NET Web API

Answer 2

更简单的方法是使用Web API 2 ApiController中的方便方法。

[HttpPost]
public async Task<IHttpActionResult> Create([FromBody] AType payload)
{
    if (payload == null) 
    {
        return BadRequest("Must provide payload");
    }

    await Task.Delay(1);

    var t = new T { Id = 0, Name = payload.tName, Guid = Guid.NewGuid() };

    var response = new MyResponse { T = t };

    return Ok(response);
}

web api：将数据添加到HttpResponseMessage

2 个答案: