.net core middleware 捕获 request和response

        private readonly RequestDelegate _next;

        /// <summary>
        /// set trace context
        /// </summary>
        /// <param name="next"></param>
        public RequestResponseLoggerMiddleware(RequestDelegate next)
        {
            _next = next;
        }


        
        public async Task Invoke(HttpContext context)
        {
            if (context != null)
            {
                var endpoint = context.GetEndpoint();
                
                if (endpoint != null)
                {
                    var attribute = endpoint.Metadata.OfType<MarkAttribute>().SingleOrDefault();

                    if(attribute != null)
                    {
                        if (!attribute.IsEnable)
                            return;

                        //enable stream can be read more than once
                        context.Request.EnableBuffering(); 
                        

                        var originalResponseStream = context.Response.Body;
                        

                        //do not use using to dispose reader
                        var requestReader = new StreamReader(context.Request.Body);
                        var requestStr = await requestReader.ReadToEndAsync();
                        Activity.Current?.SetTag("Request", requestStr);
                        
                        //set request stream pointer
                        context.Request.Body.Position = 0;
            

                        //response.Stream cant be read, set a new stream to read
                        using var memoryStream = new MemoryStream();
                        context.Response.Body = memoryStream;

                        //execute api
                        await _next(context);

                        memoryStream.Position = 0;

                        var responseReader = new StreamReader(memoryStream);
                        var responseStr = await responseReader.ReadToEndAsync();
                        Activity.Current?.SetTag("Response", responseStr);

                        memoryStream.Position = 0;
                        await memoryStream.CopyToAsync(originalResponseStream);
                        context.Response.Body = originalResponseStream;
                        return;
                    }
                    
                }

            }

            await _next(context);
        }