Java GUI似乎是空白的（swing + awt）

Question

我无法让GUI包含我的任何JButton或JTextField。我有两个类包含我的主要方法和框架构造函数的一个“SnowballFight”类。然后我也有“GameBoard”，它设置我的GUI。我的问题是我的GUI出现，但显示为空。

“打雪仗” 类：

package snowballfight; 
import java.awt.BorderLayout; 
import javax.swing.JFrame; 
import javax.swing.JButton; 
import javax.swing.JTextField; 
import javax.swing.JPanel; 
import java.awt.Color; 
import java.awt.GridLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 

public class SnowballFight extends JFrame implements ActionListener{ 
    public SnowballFight(){ 
     setLayout(new BorderLayout(1,2)); 
    } 
    public static void main(String[] args) { 
     SnowballFight frame = new SnowballFight(); 
     GameBoard game = new GameBoard(frame); 
    } 
    public void actionPerformed(ActionEvent event) { 
    } 
} 

“游戏键盘” 类：

package snowballfight; 
import java.awt.BorderLayout; 
import javax.swing.JFrame; 
import javax.swing.JButton; 
import javax.swing.JTextField; 
import javax.swing.JPanel; 
import java.awt.Color; 
import java.awt.GridLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 

public class GameBoard extends JFrame implements ActionListener{ 
    private JButton[][] game = new JButton[10][10]; 
    private JTextField display = new JTextField("Welcome to the SnowBall fight!"); 
    private Opponent[] opponents = new Opponent[4]; 
    public GameBoard(SnowballFight frame){ 
     JPanel panel = new JPanel(); 
     panel.setLayout(new GridLayout(10, 10)); 
     for (int row = 0; row < game.length; row++) { 
      for (int col = 0; col < game[row].length; col++) { 
       game[row][col] = new JButton(); 
       game[row][col].setBackground(Color.gray); 
       game[row][col].addActionListener(this); 
       panel.add(game[row][col]); 
      } 
     } 
     add(display, BorderLayout.NORTH); 
     add(panel, BorderLayout.SOUTH); 
     frame.setTitle("Snowball Fight"); 
     frame.setSize(200, 150); 
     frame.setLocationRelativeTo(null); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.setVisible(true); 
    } 
    public boolean isGameOver(){ 
     for (int opponent = 0; opponent < opponents.length; opponent++) { 
      if(opponents[opponent].isSoaked() == false){ 
       return false; 
      } 
     } 
     return true; 
    } 
    public void actionPerformed(ActionEvent event) { 
    } 
} 

Answer 1

不知道为什么有两个帧的延长JFrame，但我觉得你将display和panel添加到错误的帧。

尝试改变：

add(display, BorderLayout.NORTH); 
    add(panel, BorderLayout.SOUTH); 

到：

frame.add(display, BorderLayout.NORTH); 
    frame.add(panel, BorderLayout.SOUTH); 

Answer 2

你永远不会让GameBoardJFrame可见

game.setVisible(true); 

一些注意事项：

• 框架SnowballFight没有明显的功能
• 这是没有必要的，因为没有的功能被添加
• 读The Use of Multiple JFrames, Good/Bad Practice?