我一直在做一个项目，这就是我的工作。我从数据库中获取数据并将它们放在一个对象数组中，这些对象是带有一些编辑的JPanel。所以这是问题所在。回到主程序中我写了一个循环，以便它将actionlisteners添加到这些JPanels中的按钮。但它不起作用。
package testgen;
import java.awt.CardLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
public class TestGen extends JFrame implements ActionListener {
private static JPanel container;
private static StudentIntro p2;
private static MainPanel p1;
private static InstructorIntro p3;
private final CardLayout cards;
private boolean isValid;
private final DBHandler DB;
private QPanel[] panels = new QPanel[10];
private final LoadingPanel n = new LoadingPanel();
public TestGen() {
DB = new DBHandler();
this.cards = new CardLayout();
container = new JPanel();
container.setLayout(cards);
p1 = new MainPanel();
p2 = new StudentIntro();
p3 = new InstructorIntro();
container.add(p1, "mainPanel");
container.add(p2, "studentPanel");
container.add(p3, "instructorPanel");
container.add(n, "loading");
p1.goNext.addActionListener(this);
p2.back.addActionListener(this);
p2.start.addActionListener(this);
n.startTest.addActionListener(this);
cards.show(container, "1");
}
public static void main(String[] args) {
TestGen c = new TestGen();
c.add(container);
c.setSize(650, 550);
c.setResizable(false);
c.setLocationRelativeTo(null);
c.setVisible(true);
c.setTitle(" Fist Bump Quiz Generator");
c.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
private boolean checkValid(MainPanel p) {
String id = p.getId();
if (id.isEmpty()) {
JOptionPane.showMessageDialog(null, "Invalid ID or Password!", "Try Again", JOptionPane.WARNING_MESSAGE);
return false;
}
String sql = "SELECT passwords FROM `instructors` WHERE username ='" + id + "'";
if (DB.checkConn() == false) {
return false;
}
String right = DB.fetchPassword(sql);
char[] password = p.getPassword();
String inPass = "";
for (int i = 0; i < password.length; i++) {
inPass = inPass + password[i];
}
if (right.equals(inPass) == false) {
JOptionPane.showMessageDialog(null, "Invalid ID or Password!", "Try Again", JOptionPane.WARNING_MESSAGE);
return false;
}
return true;
}
private void addListners() {
addL();
for (int i = 0; i < 10; i++) {
container.add(panels[i], "question" + (i + 1));
if (i == 0) {
if (panels[i].getQuesType().equals("TF")) {
((TFPanel) panels[i]).goPrev.setEnabled(false);
} else if (panels[i].getQuesType().equals("Blank")) {
((FillBlank) panels[i]).goPrev.setEnabled(false);
} else {
((ShortAns) panels[i]).goPrev.setEnabled(false);
}
}
if (i == 9) {
if (panels[i].getQuesType().equals("TF")) {
((TFPanel) panels[i]).goNext.setText("Submit Test");
} else if (panels[i].getQuesType().equals("Blank")) {
((FillBlank) panels[i]).goNext.setText("Submit Test");
} else {
((ShortAns) panels[i]).goNext.setText("Submit Test");
}
}
}
}
private void quesPopulate() {
Runnable r = new Runnable() {
@Override
public void run() {
if (DB.checkConn(false) == true) {
cards.show(container, "loading");
}
return;
}
};
Thread t = new Thread(r);
t.start();
Runnable r2 = new Runnable() {
@Override
public void run() {
if (DB.checkConn() == true) {
panels = DB.fetchQuestion();
addListners();
n.startTest.setVisible(true);
n.loadimg.setVisible(false);
}
}
};
Thread t2 = new Thread(r2);
t2.start();
}
private void addL() {
for (int i = 0; i < 10; i++) {
switch (panels[i].getQuesType()) {
case "TF":
((TFPanel) panels[i]).goPrev.addActionListener(this);
((TFPanel) panels[i]).goNext.addActionListener(this);
System.out.println("Action Added " + i);
break;
case "Blank":
((FillBlank) panels[i]).goPrev.addActionListener(this);
((FillBlank) panels[i]).goNext.addActionListener(this);
System.out.println("Action Added " + i);
break;
case "Short":
((ShortAns) panels[i]).goPrev.addActionListener(this);
((ShortAns) panels[i]).goNext.addActionListener(this);
System.out.println("Action Added " + i);
break;
}
}
}
@Override
public void actionPerformed(ActionEvent e) {
try {
if (e.getSource() == p1.goNext && p1.goNext.isEnabled() && "Login".equals(p1.goNext.getText())) {
isValid = checkValid(p1);
if (isValid) {
cards.show(container, "instructorPanel");
}
} else if (e.getSource() == p1.goNext && p1.goNext.isEnabled() && p1.goNext.getText().equals("Get Started!")) {
try {
if (p1.getName().isEmpty()) {
throw new RuntimeException();
} else {
cards.show(container, "studentPanel");
p2.setLabel(p1.getName());
}
} catch (Exception ex) {
JOptionPane.showMessageDialog(null, "Please Enter your Name", "Try Again", JOptionPane.WARNING_MESSAGE);
}
} else if (e.getSource() == p2.back) {
cards.show(container, "mainPanel");
} else if (e.getSource() == n.startTest) {
System.out.println("button Pressed");
cards.show(container, "question2");
} else if (e.getSource() == p2.start) {
Runnable r2 = new Runnable() {
@Override
public void run() {
quesPopulate();
}
};
Thread t2 = new Thread(r2);
t2.start();
Runnable r = new Runnable() {
@Override
public void run() {
addListners();
}
};
Thread t = new Thread(r);
} else if (e.getSource() == ((TFPanel) panels[9]).goNext) {
int finals = 0;
for (int j = 0; j < 10; j++) {
panels[j].checkAnswer();
if (panels[j].isScore() == true) {
finals++;
}
}
System.out.println(finals);
} else {
for (int i = 0; i < 10; i++) {
if (panels[i].getQuesType().equals("TF")) {
System.out.println("button Pressed");
if (e.getSource() == ((TFPanel) panels[i]).goPrev) {
cards.show(container, "question" + (i));
} else if (e.getSource() == ((TFPanel) panels[i]).goNext) {
cards.show(container, "question" + (i + 2));
}
} else if (panels[i].getQuesType().equals("Blank")) {
System.out.println("button Pressed");
if (e.getSource() == ((FillBlank) panels[i]).goPrev) {
cards.show(container, "question" + (i));
} else if (e.getSource() == ((FillBlank) panels[i]).goNext) {
cards.show(container, "question" + (i + 2));
}
} else if (panels[i].getQuesType().equals("Short")) {
System.out.println("button Pressed");
if (e.getSource() == ((ShortAns) panels[i]).goPrev) {
cards.show(container, "question" + (i));
} else if (e.getSource() == ((ShortAns) panels[i]).goNext) {
cards.show(container, "question" + (i + 2));
}
}
}
}
} catch (Exception ex) {
}
}
} 编辑（添加格式化的完整类）我无法提供可运行的程序，因为它有多个类。我也从面板类外部使用ActionListener，因为我需要在按钮上切换卡片布局按。 在那种情况下的任何帮助？在此先感谢：）