C adds two methods to the picturebox control with the image selected state

Method 1:

The easy way is to change the borderstyle style of the picturebox control

  currentSelectPicBox.BorderStyle = BorderStyle.Fixed3D;
                    currentSelectPicBox Refresh(); // forces the control to redraw

Method 2

Add a rectangle to the picturebox control,  , but this method is slow in the application.

How to add a rectangle:
                      Graphics pictureborder = currentSelectPicBox.CreateGraphics();
                      Pen pen = new Pen(Color.Red, 2);
                      pictureborder.DrawRectangle(pen, currentSelectPicBox.ClientRectangle.X, currentSelectPicBox.ClientRectangle.Y, currentSelectPicBox.ClientRectangle.X + currentSelectPicBox.ClientRectangle.Width, currentSelectPicBox.ClientRectangle.Y + currentSelectPicBox.ClientRectangle.Height);
Method to remove a rectangle

currentSelectPicBox.Invalidate();

If you have a better idea, please share   with me