我的JPanel startPan应该在applet启动时显示，但是现在只显示JButton setupGameBut。但是，如果我单击setupGameBut然后单击cancelBut返回startPan，它将显示规则但仍然不显示JLabel headingLab（它确实显示在setupPan上）。
除此之外，它还显示当前正在显示的面板后面的其他面板的组件，但它们无法与之交互。
点击一个按钮，如果你在加载下一张卡之前将光标移离它，它将不会更新到应该显示在那里的按钮，直到再次鼠标移开。我有一种感觉，我正在做一些根本错误的代码，我有这些问题，但我不确定。
/*
*Java Version: 1.8.0_25
*Author: Peadar Ó Duinnín
*Student Number: R00095488
*/
package As1;
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Choice;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class AUIApplet extends JApplet {
private final int APPLET_WIDTH;
private final int APPLET_HEIGHT;
private final int[] highScores = new int[3];
private int currentScore;
final Font normalFont = new Font("Cambria", Font.PLAIN, 18);
final Font headingFont = new Font("Cambria", Font.BOLD, 24);
JPanel contPan, startPan, setupPan, gamePan, scorePan, startInfoPan, gameInfoPan, rulePan, setupInfoPan, gameOptPan;
JButton setupGameBut, cancelBut, endGameBut, startGameBut;
JLabel highScoreLab, currentScoreLab, headingLab, rulesLab, difficultyScoreLab;
Choice difficulty;
CardLayout cl = new CardLayout();
public AUIApplet() {
this.APPLET_HEIGHT = 400;
this.APPLET_WIDTH = 600;
for (int i : highScores) {
i = 0;
}
}
@Override
public void init() {
//set applet size
setSize(APPLET_WIDTH, APPLET_HEIGHT);
//start screen
startPan = new JPanel();
startPan.setLayout(new BorderLayout());
//setup screen
setupPan = new JPanel();
setupPan.setLayout(new BorderLayout());
setupGameBut = new JButton("New Game");
cancelBut = new JButton("Cancel");
//game screen
gamePan = new JPanel();
gamePan.setLayout(new BorderLayout());
endGameBut = new JButton("Quit Game");
//heading label
headingLab = new JLabel("Number Memory");
headingLab.setFont(headingFont);
//rule panel
rulePan = new JPanel();
rulePan.setLayout(new GridLayout(8,1));
rulePan.add(new JLabel("Rules:"));
rulePan.add(new JLabel("1. You will be shown a series of numbers, one at a time."));
rulePan.add(new JLabel("2. You must recite the series of numbers after the last number has been displayed."));
rulePan.add(new JLabel("3. After each correct recitation of the sequence, another sequence will play with one extra number."));
rulePan.add(new JLabel("Note: You can decrease/increase the time each number displays for by changing the difficulty."));
//difficulty selection
difficulty = new Choice();
difficulty.add("Easy");
difficulty.add("Normal");
difficulty.add("Hard");
difficulty.add("Extra Hard");
difficulty.select(1);
difficultyScoreLab = new JLabel("" + highScores[1] + "");
switch(difficulty.getSelectedIndex()) {
case 0: difficultyScoreLab.setText("" + highScores[0] + "");
break;
case 1: difficultyScoreLab.setText("" + highScores[1] + "");
break;
case 2: difficultyScoreLab.setText("" + highScores[2] + "");
break;
case 3: difficultyScoreLab.setText("" + highScores[3] + "");
break;
}
//game option panel
gameOptPan = new JPanel();
gameOptPan.setLayout(new GridLayout(1,2));
startGameBut = new JButton("Start Game");
gameOptPan.add(startGameBut);
gameOptPan.add(difficulty);
//start info panel
startInfoPan = new JPanel();
startInfoPan.setLayout(new BorderLayout());
startInfoPan.add(rulePan, BorderLayout.CENTER);
//setup info panel
setupInfoPan = new JPanel();
setupInfoPan.setLayout(new BorderLayout());
setupInfoPan.add(gameOptPan, BorderLayout.SOUTH);
setupInfoPan.add(new JLabel("High Score:"), BorderLayout.NORTH);
setupInfoPan.add(difficultyScoreLab, BorderLayout.CENTER);
//game info panel
gameInfoPan = new JPanel();
gameInfoPan.setLayout(new BorderLayout());
//score panel
scorePan = new JPanel();
scorePan.setLayout(new GridLayout(10,1));
highScoreLab = new JLabel("High Score: " + highScores[difficulty.getSelectedIndex()] + " ");
currentScoreLab = new JLabel("Current Score: " + currentScore + " ");
scorePan.add(highScoreLab);
scorePan.add(currentScoreLab);
//adding to start panel
startPan.add(setupGameBut, BorderLayout.SOUTH);
startPan.add(headingLab, BorderLayout.NORTH);
startPan.add(startInfoPan, BorderLayout.CENTER);
//adding to setup panel
setupPan.add(cancelBut, BorderLayout.SOUTH);
setupPan.add(headingLab, BorderLayout.NORTH);
setupPan.add(setupInfoPan, BorderLayout.CENTER);
//adding to game panel
gamePan.add(endGameBut, BorderLayout.SOUTH);
gamePan.add(headingLab, BorderLayout.NORTH);
gamePan.add(gameInfoPan, BorderLayout.CENTER);
gamePan.add(scorePan, BorderLayout.EAST);
//setting up container panel and adding each screen to it
contPan = new JPanel();
contPan.setLayout(cl);
contPan.add(startPan, "Start Applet Screen");
contPan.add(setupPan, "Setup Game Screen");
contPan.add(gamePan, "New Game Screen");
//action listeners
setupGameBut.addActionListener((ActionEvent e) -> {
newGame();
});
startGameBut.addActionListener((ActionEvent e) -> {
startGame();
});
cancelBut.addActionListener((ActionEvent e) -> {
quitGame();
});
endGameBut.addActionListener((ActionEvent e) -> {
quitGame();
});
//add container panel
this.add(contPan);
}
@Override
public void paint(Graphics g) {
}
public void newGame() {
cl.show(contPan, "Setup Game Screen");
}
public void startGame() {
cl.show(contPan, "New Game Screen");
}
public void quitGame() {
cl.show(contPan, "Start Applet Screen");
if (currentScore > highScores[difficulty.getSelectedIndex()]) {
highScores[difficulty.getSelectedIndex()] = currentScore;
}
currentScore = 0;
}
@Override
public Insets getInsets() {
return new Insets(10, 10, 10, 10);
}
}
答案 0 :(得分：2)
不要覆盖paint()。
很少有理由这样做，我想不出任何有空方法的理由。空方法必然会导致问题
我稍后在我的程序中使用它来绘制东西
仍然不要覆盖paint（）。自定义绘制是通过覆盖JPanel（或JComponent）的paintComponent(...)方法完成的，然后将面板添加到applet中。
阅读Custom Painting上Swing教程中的部分，了解更多信息和示例。