ImageMiddleware

public class ImageMiddleware
    {
        private readonly RequestDelegate _next;
        private readonly string _path;

        public ImageMiddleware(RequestDelegate next, string path)
        {
            _next = next;
            this._path = path;
        }

        public async Task Invoke(HttpContext context)
        {
            if (context.Request.Path.Equals(this._path, StringComparison.OrdinalIgnoreCase))
            {
                this.HandleImageRequest(context);
            }
            else
            {
                await this._next.Invoke(context);
            }
        }

        private async void HandleImageRequest(HttpContext context)
        {
            var width = this.GetQueryStringValue(context, "w");
            var height = this.GetQueryStringValue(context, "h");
            var imageId = this.GetQueryStringValue(context, "id");

            if (imageId <= 0)
            {
                throw new ArgumentNullException($"id : {imageId} must be greater than zero");
            }

            if (width <= 0 || height <= 0)
            {
                throw new ArgumentNullException($"Width : {width} && height : {height} must be greater than zero");
            }

            var image = ImageManager.GetImage(imageId);

            if (image != null)
            {
                using (MagickImage magickImage = new MagickImage(image.ImageBinary))
                {
                    if (magickImage.Height > height && magickImage.Width > width)
                    {
                        magickImage.Resize(width, height);
                    }
                    var buffer = magickImage.ToByteArray();
                    context.Response.Clear();
                    context.Response.ContentType = image.MimeType;
                    await context.Response.Body.WriteAsync(buffer, 0, buffer.Length);
                }
            }
            else
            {
                context.Response.Clear();
                await context.Response.WriteAsync($"Image Not Found With ID {imageId}");
            }
        }

        private int GetQueryStringValue(HttpContext context, string prmName)
        {
            int val = 0;

            var wQuery = context.Request.Query[prmName];

            if (!string.IsNullOrWhiteSpace(wQuery))
            {
                int.TryParse(wQuery, out val);
            }

            return val;
        }
    }