有没有办法在.NET Core FilterAttribute中获取请求体？

Question

我的请求样本

http://localhost:8065/api/note
POST
content-type:application/json
request body: { "id" : "1234", "title" : "test", "status" : "draft"}

应该是

{ "msg" : "ok", "code" : 1}

那个行动

public async Task<IActionResult> Post([FromBody]NoteModel model)

---

为了自动记录每个请求,我创建了一个属性来完成这项工作.该属性如下所示:(来自Microsoft Docs)

public class SampleActionFilterAttribute : TypeFilterAttribute
{
    public SampleActionFilterAttribute():base(typeof(SampleActionFilterImpl))
    {
    }

    private class SampleActionFilterImpl : IActionFilter
    {
        private readonly ILogger _logger;
        public SampleActionFilterImpl(ILoggerFactory loggerFactory)
        {
            _logger = loggerFactory.CreateLogger<SampleActionFilterAttribute>();
        }

        public void OnActionExecuting(ActionExecutingContext context)
        {

        }

        public void OnActionExecuted(ActionExecutedContext context)
        {
            _logger.LogDebug("[path]" + context.HttpContext.Request.Path);
            _logger.LogDebug("[method]" + context.HttpContext.Request.Method);
            _logger.LogDebug("[body]"); //log request body, expectation: { "id" : "1234", "title" : "test", "status" : "draft"}
            _logger.LogDebug("[statuscode]" + context.HttpContext.Response.StatusCode);
            _logger.LogDebug("[response]"); //log response
        }
    }
}

我尝试使用streamReader来获取请求体只获取空字符串.

StreamReader reader = new StreamReader(context.HttpContext.Request.Body);
string text = reader.ReadToEnd();

那是因为身体是由[fromBody]从控制器读取的,所以流不能被读取两次？如果是这样,我怎么能在OnActionExecuted方法中得到请求体和响应？

---

更新:

我刚刚将Set的代码复制到我的项目中,而不是工作.这是调试gif

Answer 1

因此,对于" 在中间件 "中记录/读取请求主体的最佳方法,以下内容应该有效:

// using Microsoft.AspNetCore.Http.Internal;

public class SampleActionFilterAttribute : TypeFilterAttribute
{
    ... 

    public void OnActionExecuting(ActionExecutedContext context)
    {
        // read body before MVC action execution
        string bodyData = ReadBodyAsString(context.HttpContext.Request);
    }

    private string ReadBodyAsString(HttpRequest request)
    {
        var initialBody = request.Body; // Workaround

        try
        {
            request.EnableRewind();

            using (StreamReader reader = new StreamReader(request.Body))
            {
                string text = reader.ReadToEnd();
                return text;
            }
        }
        finally
        {
            // Workaround so MVC action will be able to read body as well
            request.Body = initialBody; 
        }

        return string.Empty;
    }
 }

在Read请求体中描述的类似方法两次 SO post

更新:ReadBodyAsString如果在中间件中使用,则上述方法将起作用,而不是在动作过滤器中使用.不同之处在于当动作过滤器正在调用(即使是OnActionExecuting)时,已经读取了主体流并且[FromBody] model已经填充了该主体流.

好的nesw是这样的,因此可以通过使用直接在动作过滤器中获得模型context.ActionArguments["<model_name>"].在你的情况下:

public void OnActionExecuted(ActionExecutedContext context)
{
   var model = context.ActionArguments["model"] as NoteModel;
}