Question

public void EncryptFile()
    {            
        OpenFileDialog dialog = new OpenFileDialog();
        dialog.Filter = "JPEG Files (*.jpeg)|*.jpeg|PNG Files (*.png)|*.png|All files (*.*)|*.*";
        dialog.InitialDirectory = @"C:\";
        dialog.Title = "Please select an image file to encrypt.";
        if (dialog.ShowDialog() == DialogResult.OK)
        {
            byte[] ImageBytes = File.ReadAllBytes(dialog.FileName);

            foreach (byte X in ImageBytes)
            {
                //How can I take byte "X" and add a numerical value to it?
            }
        }             
    }

So, I’m trying to encrypt an image file by just converting it to byte[] array and then adding a numerical value to each byte.

How can I add a numerical value to a byte?

Answer 1

You just add it. The problem is that you can’t modify the value in your foreach loop there. You actually want a for loop:

for(int k = 0; k < ImagesBytes.Length; k++){
   ImageBytes[k] = (byte) (ImageBytes[k] + 5); // needs a cast
}