在ApiController中添加自定义响应标头 [英] Add a custom response header in ApiController

问题描述

直到现在，我有一个GET方法，如下所示:

Until now, I had a GET method that looked like the following:

protected override async Task<IHttpActionResult> GetAll(QueryData query)
{
     // ... Some operations

     //LINQ Expression based on the query parameters
     Expression<Func<Entity, bool>> queryExpression = BuildQueryExpression(query);

     //Begin to count all the entities in the repository
     Task<int> countingEntities = repo.CountAsync(queryExpression);

     //Reads an entity that will be the page start
     Entity start = await repo.ReadAsync(query.Start);

     //Reads all the entities starting from the start entity
     IEnumerable<Entity> found = await repo.BrowseAllAsync(start, queryExpression);

     //Truncates to page size
     found = found.Take(query.Size);

     //Number of entities returned in response
     int count = found.Count();

     //Number of total entities (without pagination)
     int total = await countingEntities;

     return Ok(new {
          Total = total,
          Count = count,
          Last = count > 0 ? GetEntityKey(found.Last()) : default(Key),
          Data = found.Select(e => IsResourceOwner(e) ? MapToOwnerDTO(e) : MapToDTO(e)).ToList()
     });
}

这就像一种魅力，很好.但是，最近我被告知发送响应元数据(即Total，Count和Last属性)作为响应自定义标头，而不是响应正文.

This worked like a charm and it was good. However, I was told recently to send the response metadata (that is, Total, Count and Last properties) as response custom headers instead of the response body.

我无法从ApiController访问Response.我想到了过滤器或属性，但是如何获取元数据值?

I cannot manage to access the Response from the ApiController. I thought of a filter or attribute, but how would I get the metadata values?

我可以将所有这些信息保留在响应中，然后有一个过滤器，该过滤器将在发送给客户端之前反序列化响应，并使用标头创建一个新的响应器，但这似乎很麻烦而且很糟糕.

I can keep all this information on the response and then have a filter that will deserialize the response before being sent to the client, and create a new one with the headers, but that seems troublesome and bad.

是否可以直接在ApiController上通过此方法添加自定义标头?

Is there a way to add custom headers directly from this method on an ApiController?

推荐答案

我已输入评论，这是我的完整答案.

I have entered comments, here is my complete answer.

您将需要创建一个自定义过滤器并将其应用于您的控制器.

You will need to create a custom filter and apply that to your controller .

public class CustomHeaderFilter : ActionFilterAttribute
{
    public override void OnActionExecuted(HttpActionExecutedContext actionExecutedContext)
    {
       var count = actionExecutedContext.Request.Properties["Count"];
       actionExecutedContext.Response.Content.Headers.Add("totalHeader", count);
    }
}

在您的控制器中

  public class AddressController : ApiController
        {
            public async Task<Address> Get()
            {
               Request.Properties["Count"] = "123";
            }
    }

这篇关于在ApiController中添加自定义响应标头的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！