Resizing image proportionally in ASP.NET C# by specifying either Height or Width

Question

I need a code that will allow me to resize images, but with the following functionality:

1) resize image upon upload

2) Resize image proportionally by specifying

Answer 1

This is how is did in my project

On Button click while uploading file:

System.Drawing.Bitmap bmpPostedImage = new System.Drawing.Bitmap(File1.PostedFile.InputStream);
     System.Drawing.Image objImage = ScaleImage(bmpPostedImage, 81);
     objImage.Save(SaveLocation,ImageFormat.Png);
     lblmsg.Text = "The file has been uploaded.";

---

public static System.Drawing.Image ScaleImage(System.Drawing.Image image, int maxHeight)
        {
            var ratio = (double)maxHeight / image.Height;

            var newWidth = (int)(image.Width * ratio);
            var newHeight = (int)(image.Height * ratio);

            var newImage = new Bitmap(newWidth, newHeight);
            using (var g = Graphics.FromImage(newImage))
            {
                g.DrawImage(image, 0, 0, newWidth, newHeight);
            }
            return newImage;
        }

More Detail Click here

https://codepedia.info/how-to-resize-image-while-uploading-in-asp-net-using-c/