public void ResizeImage(string origFileLocation, string newFileLocation, string newFileName, int newWidth, int maxHeight, bool resizeIfWider)
       {
           try
           {
               System.Drawing.Image FullSizeImage = System.Drawing.Image.FromFile(origFileLocation);
               // Ensure the generated thumbnail is not being used by rotating it 360 degrees
               FullSizeImage.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipNone);
               FullSizeImage.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipNone);
               if (resizeIfWider)
               {
                   if (FullSizeImage.Width <= newWidth)
                   {
                       //newWidth = FullSizeImage.Width;
                   }
               }
               int newHeight = FullSizeImage.Height * newWidth / FullSizeImage.Width;
               if (newHeight > maxHeight) // Height resize if necessary
               {
                   //newWidth = FullSizeImage.Width * maxHeight / FullSizeImage.Height;
                   newHeight = maxHeight;
               }
               newHeight = maxHeight;
               // Create the new image with the sizes we've calculated
               System.Drawing.Image NewImage = FullSizeImage.GetThumbnailImage(newWidth, newHeight, null, IntPtr.Zero);
               FullSizeImage.Dispose();
               NewImage.Save(Path.Combine(newFileLocation, newFileName));
           }
           catch (Exception ex)
           {
               lblError.Text = ex.Message;
           }
       }


       origFileLocation : Original file location(Source Folder)
       newFileLocation  : New file location(Destination Folder)

       newFileName : new file name to be saved to destination folder

你可以如果您不想要图像大小调整逻辑，则更改该功能

You may alter the function if you do not want image resize logic