Why will image not add when JFrame has .setSize

Question

I'm a somewhat novice programmer and I'm have some trouble adding an image to my frame. While I know how to add images generally, this specific case it does not work.

public class Tutorial extends JFrame{

    Tutorial(){

        JFrame frame = new JFrame("ImageTutorial");
        frame.setVisible(true);
        frame.setSize(750,850);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLayout(null);
        ImageIcon image = new ImageIcon(getClass().getResource("Green Block.png"));
        JLabel imagelabel = new JLabel(image);
        imagelabel.setBounds(10, 10, 75, 75);
        imagelabel.setOpaque(true);
        frame.add(imagelabel);  

Now, I've located the problem but I don't understand 'why' its a problem. When I remove

        frame.setSize(750,850);

the image shows, but when its there it doesn't. How can the frame's size impact the image showing and how can I get around it?

Answer 1

Just curious, logically, what makes you think a frame should be visible before you add any components? Logically speaking, wouldn't it seem right to add your components first, then make the frame visible. It's like displaying a painting in an art gallery even before the painter has painted anything on it. It just makes no sense. I highly doubt setting the size has anything to do with it. IF you don't set the size of the frame, then the frame appears as small as possible. When you resize the frame, it causes a repaint, then showing the label you add. But generally, you want to always set frame visible after all you components are added, to avoid this problem.

Side note: You should stay away from null layouts. You need to learn to use Layout Managers and let them do the dynamic sizing and locating for you.