Question

how to delete image from picture box when user press “del” key…I dont find any keypress or keydown events for PB.

    private void topRight_pbx_MouseClick(object sender, MouseEventArgs e)
          {
           imgSelected=true;

           //need to accept "delete"key from keyboard?

           topRight_pbx.Image = null;
            topRFile = "";

           }

Answer 1

Change your imgSelected to something like:

private PictureBox picSelected = null;

On your picturebox click set this variable to the sender:

picSelected = (PictureBox)sender;

Then on the keydown of form or the control that has focus you run the image removal code
(Example for form):

private void Form1_KeyDown(object sender, KeyEventArgs e)
{
   if (e.KeyCode == Keys.Delete)
      picSelected.Image = null;
}