Asp.Net Core：使用 ImageSharp 压缩图像并使用 Blob 保存到数据库

Question

I tried to compress the image using Imagesharp Nuget package and save to my sql database as a Blob file but the problem is image is compressed successfully.. but not the compressed image only store Original one , Example: Pictureone.jpg image size is 3mb..after uploading the image size is compressed like 40kb but when i applied to save in database that compressed file its save original one (3mb). Here is my code

Model BlobImage.cs

namespace ImageToDb.Models
{
    public class BlobImg
    {
        public int id { get; set; }
        public string name { get; set; }
        public byte[] image { get; set; }
    }
}

ImageController.cs

using SixLabors.ImageSharp;
using SixLabors.ImageSharp.Processing;

[HttpPost]
        public async Task<IActionResult> Index(IFormFile file, BlobImg bolb)
        {
            string fileName = string.Empty;
            string path = string.Empty;
            var files = HttpContext.Request.Form.Files;
            if (file.Length > 0)
            {
                
                using (var img = Image.Load(file.OpenReadStream()))
                {
                    string newSize = ResizeImage(img, 500, 500);
                    string[] aSize = newSize.Split(',');
                    img.Mutate(h => h.Resize(Convert.ToInt32(aSize[1]), Convert.ToInt32(aSize[0])));
                    
                    //This section save the image to database using blob
                    foreach (var item in files)
                    {
                        if (item.Length > 0)
                        {
                            using (var stream = new MemoryStream())
                            {
                                await item.CopyToAsync(stream);
                                bolb.image = stream.ToArray();
                            }
                        }
                    }

                    
                }

               ;
            }
            return View();
        }

        public string ResizeImage(Image img, int maxWidth, int maxHeight)
        {
            if (img.Width > maxWidth || img.Height > maxHeight)
            {
                double widthRatio = (double)img.Width / (double)maxWidth;
                double heightRatio = (double)img.Height / (double)maxHeight;
                double ratio = Math.Max(widthRatio, heightRatio);
                int newWidth = (int)(img.Width / ratio);
                int newHeight = (int)(img.Height / ratio);
                return newHeight.ToString() + "," + newWidth.ToString();
            }
            else
            {
                return img.Height.ToString() + "," + img.Width.ToString();
            }
        }

Answer 1

You compress the image on this line:

img.Mutate(h => h.Resize(Convert.ToInt32(aSize[1]), Convert.ToInt32(aSize[0])));

Then you don't reference it again in any of subsequent code and (I assume) save everything in HttpContext.Request.Form.Files instead. Rather than doing this, save the "img" object to the database instead. I can't see any code which actually saves anything to the database regardless but I suspect this is the problem based on your description. So your code is most likely fine you're just saving the wrong thing.

Try this, you'll need to determine the image format yourself:

public async Task<IActionResult> Index(IFormFile file, BlobImg bolb)
    {
        if (file.Length > 0)
        {
            
            using (var img = Image.Load(file.OpenReadStream()))
            {
                string newSize = ResizeImage(img, 500, 500);
                string[] aSize = newSize.Split(',');
                img.Mutate(h => h.Resize(Convert.ToInt32(aSize[1]), Convert.ToInt32(aSize[0])));

                //This section save the image to database using blob
                using (var ms = new MemoryStream())
                {
                    img.Save(ms, imageFormat);
                    bolb.image = ms.ToArray();
                }   
            }
        }
        return View();
    }