尝试使用包含两个 JButton 的 JPanel 制作 JFrame

Question

I am a beginner here and I am trying to make a GUI that will display two buttons, addCard and deleteCard. However, the compiler is showing errors, and I cannot seem to find the error. Thank you in advance!

package studyfast;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Scratch{
    JFrame projectFrame = new JFrame();
    projectFrame.setSize(1000, 600);
    projectFrame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

    JPanel panelEditCard = new JPanel();

    JButton addCard = new JButton();
    JButton deleteCard = new JButton();

    panelEditCard.add(addCard);
    panelEditCard.add(deleteCard);

    projectFrame.add(panelEditCard);
    projectFrame.setVisible(true);

    public static void main(String[] args){
        new Scratch();
    }
}

Answer 1

You need to move your code inside the Scratch class inside a constructor

package studyfast;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Scratch 
{
    JFrame projectFrame = new JFrame();
    JPanel panelEditCard = new JPanel();
    JButton addCard = new JButton();
    JButton deleteCard = new JButton();

    public Scratch()
    {
        projectFrame.setSize(1000, 600);
        projectFrame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);   

        panelEditCard.add(addCard);
        panelEditCard.add(deleteCard);

        projectFrame.add(panelEditCard);
        projectFrame.setVisible(true);
      }

   public static void main(String[] args) 
   {
       new Scratch();
   }
}