java - Gui 按钮不起作用

Question

我是新来的，如果有点难以理解，很抱歉。基本上我的问题是我必须制作一个 GUI Hangman 游戏，我目前正在尝试让猜测按钮工作，但它似乎不想这样做。

import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.MatteBorder;
import java.awt.Color;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JLabel;

public class Hangman2 {

  static final int maxguess = 8;
  static final int maxletter = 'z' - 'a' + 1;
  private JFrame frame;
  private JTextField textField;
  public int guess;

  /**
   * Launch the application.
   */
  public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
      public void run() {
        try {
          Hangman2 window = new Hangman2();
          window.frame.setVisible(true);
        } catch (Exception e) {
          e.printStackTrace();
        }
      }
    });
  }

  /**
   * Create the application.
   */
  public Hangman2() {
    initialize();
  }

  /**
   * Initialize the contents of the frame.
   */
  private void initialize() {

    frame = new JFrame();
    frame.setBounds(100, 100, 450, 300);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().setLayout(null);

    JPanel panel = new JPanel();
    panel.setBounds(0, 0, 450, 206);
    panel.setBorder(new MatteBorder(1, 1, 1, 1, (Color) new Color(0, 0, 0)));
    frame.getContentPane().add(panel);

    textField = new JTextField();
    textField.setBounds(10, 211, 113, 26);
    frame.getContentPane().add(textField);
    textField.setColumns(10);

    JButton btnGuess = new JButton("Guess");
    frame.getContentPane().add(btnGuess);
    btnGuess.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        guess++;
      }
    });
    btnGuess.setBounds(6, 243, 125, 29);
    frame.getContentPane().add(btnGuess);

    int guesses = (guess);

    JLabel lblNumberOfGuesses = new JLabel("Number of guesses:" + guesses);
    lblNumberOfGuesses.setBounds(135, 216, 155, 16);
    frame.getContentPane().add(lblNumberOfGuesses);
  }
}

Answer 1

JLabel 的文本在 initialize 方法中仅设置一次。

在增加猜测之后，在您的 actionPerformed 方法中执行此操作:

public void actionPerformed(ActionEvent e) {
        guess++;
        lblNumberOfGuesses.setText("Number of guesses:" + guess);
      }

此外，在声明 ActionListener 之前声明您的 JLabel，否则您将会出错，因为在此步骤中 lblNumberOfGuesses 是未知的。