无法处理jframe窗口？

Question

在点击任何一个难度按钮后,我试图处理难度窗口,但不会发生.我试过了.dispose,frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);但我无法得到它.它只是放置还是更多？

import java.awt.FlowLayout;
import java.awt.event.*;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JTextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.GridLayout;

public class Game extends JFrame{

    public static JFrame frame = new JFrame();


    private JLabel lab;

public static void main(String[] args) {

    Game difficulty = new Game();
    difficulty.setSize(350,105);
    difficulty.setTitle("Difficulty.");
    difficulty.setVisible(true);
    difficulty.setLocationRelativeTo(null);


    /**Game sudoku = new Game();
    sudoku.setSize(900, 900);
    sudoku.setVisible(false);*/

}   


public Game(){

    setLayout(new FlowLayout());
    lab = new JLabel("Please select your difficulty.");
    add(lab);

    JButton easy;
    easy = new JButton("Easy");
    add(easy);

     easy.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e)
            {
                //Execute when button is pressed
                System.out.println("You clicked the button");
                JFrame.dispose();
            }
        });   


    JButton medium;
    medium = new JButton("Medium");
    add(medium);

    JButton hard;
    hard = new JButton("Hard");
    add(hard);

    JButton evil;
    evil = new JButton("Evil!");
    add(evil);

}
}

Answer 1

dispose()方法不是静态的，所以直接从JFrame类调用它是行不通的

JFrame.dispose();

试着做 ：

dispose();

或者处置frame您创建的对象

frame.dispose();

阅读更多关于 JFrame

Answer 2

首先,你要扩展JFrame并创建一个JFrame对象,如果我没有错,就不应该这样做.

public class Game extends JFrame{

    public static JFrame frame = new JFrame();

正如@Salah所说,JFrame不是静态的,所以它应该是:

public JFrame frame = new JFrame();

为了解决你的问题,你要处理一个新的JFrame(是的,你在一个类中有3个JFrame,而不是1,这就是你想要的),JFrame.dispose();如果你已经创建了一个对象,或者你正在扩展JFrame,那么你能够:

this.dispose(); //For the extended JFrame

要么

frame.dispose(); //For the object you created