如何删除单击 JButton 时出现的蓝色框

Question

When i click Button, the blank part of the image looks blue. Is there any way?

        left.setPressedIcon(l1);
        left.setOpaque(false);
        left.setFocusPainted(false);
        left.setBackground(new Color(0,0,0,0));
        left.setBorderPainted(false);
        left.setBounds(-15, 400, 100, 200);

Answer 1

left.setBackground(new Color(0,0,0,0));

Don't attempt to use a transparent color. Swing doesn't paint transparent colors properly. See: Backgrounds With Transparency .

In any case that is not needed be you are using

 left.setOpaque( false );

When i click Button, the blank part of the image looks blue

Try:

left.setContentAreaFilled( false );

Also:

left.setBounds(-15, 400, 100, 200);

Don't use setBounds(...) and a null layout. Swing was designed to be used with layout managers.