我一直在看我的电脑显示器,因为当我单击“开始”按钮时,我真的不知道该怎么做才能防止我的程序上的帧同时出现。
这是我的主要课程:
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.util.Random;
import javax.swing.*;
public class PopQuizDemo {
public static void main (String args[]){
PopQuizDemo();
}
public static void PopQuizDemo(){
final SimpleFrame frame = new SimpleFrame();
final JPanel main = new JPanel();
main.setSize(400,75);
main.setLayout(new GridLayout(3,1));
frame.add(main);
JLabel l1 = new JLabel("Welcome to POP Quiz!");
main.add(l1);
JLabel l2 = new JLabel("Enter your name:");
main.add(l2);
final JTextField name = new JTextField ();
main.add(name);
final JPanel panel = new JPanel();
panel.setSize(400,50);
panel.setLocation(0,225);
frame.add(panel);
JButton start = new JButton ("Start");
panel.add(start);
frame.setVisible(true);
start.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
frame.setVisible(false);
randomize();
}
});
}
public static void randomize(){
Questions q = new Questions();
int a=0;
Random randnum = new Random (System.currentTimeMillis());
java.util.HashSet<Integer> myset = new java.util.HashSet<>();
for (int count = 1; count <= 3; count++){
while (true) {
a = randnum.nextInt (3);
if(!myset.contains(a)) { myset.add(new Integer(a)); break;}
}
if(a==0){
q.one();
}
else if(a==1){
q.two();
}
else if(a==2){
q.three();
}
else{
break;
}
}
}
}
这是类问题,我在其中获得方法一(),二()和三():
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class Questions {
public static void one(){
final SimpleFrame frame = new SimpleFrame();
JPanel p1 = new JPanel();
p1.setSize(400,100);
frame.add(p1);
JLabel qu1 = new JLabel();
qu1.setText("In computers, what is the smallest and basic unit of");
JLabel qu2 = new JLabel();
qu2.setText("information storage?");
p1.add(qu1);
p1.add(qu2);
JPanel p2 = new JPanel();
p2.setSize(400,175);
p2.setLocation(0,100);
p2.setLayout(new GridLayout(2,4));
frame.add(p2);
JButton a = new JButton("a. Bit");
p2.add(a);
JButton b = new JButton("b. Byte");
p2.add(b);
JButton c = new JButton("c. Data");
p2.add(c);
JButton d = new JButton("d. Newton");
p2.add(d);
frame.setVisible(true);
final PopQuizDemo demo = new PopQuizDemo();
a.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
frame.setVisible(false);
demo.randomize();
}
});
b.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
frame.setVisible(false);
demo.randomize();
}
});
c.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
frame.setVisible(false);
demo.randomize();
}
});
d.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
frame.setVisible(false);
demo.randomize();
}
});
}//end of method
public static void two(){
final SimpleFrame frame = new SimpleFrame();
JPanel p1 = new JPanel();
p1.setSize(400,100);
frame.add(p1);
JLabel qu1 = new JLabel();
qu1.setText("Machine language is also known as __________.");
p1.add(qu1);
JPanel p2 = new JPanel();
p2.setSize(400,175);
p2.setLocation(0,100);
p2.setLayout(new GridLayout(2,4));
frame.add(p2);
JButton a = new JButton("a. Low level language");
p2.add(a);
JButton b = new JButton("b. Assembly language");
p2.add(b);
JButton c = new JButton("c. High level language");
p2.add(c);
JButton d = new JButton("d. Source code");
p2.add(d);
frame.setVisible(true);
final PopQuizDemo demo = new PopQuizDemo();
a.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
frame.setVisible(false);
demo.randomize();
}
});
b.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
frame.setVisible(false);
demo.randomize();
}
});
c.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
frame.setVisible(false);
demo.randomize();
}
});
d.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
frame.setVisible(false);
demo.randomize();
}
});
}//end of method
public static void three(){
final SimpleFrame frame = new SimpleFrame();
JPanel p1 = new JPanel();
p1.setSize(400,100);
frame.add(p1);
JLabel qu1 = new JLabel();
qu1.setText("What is the shortcut key of printing a document for");
JLabel qu2 = new JLabel();
qu2.setText("computers using Windows?");
p1.add(qu1);
p1.add(qu2);
JPanel p2 = new JPanel();
p2.setSize(400,175);
p2.setLocation(0,100);
p2.setLayout(new GridLayout(2,4));
frame.add(p2);
JButton a = new JButton("a. Ctrl + P");
p2.add(a);
JButton b = new JButton("b. Shift + P");
p2.add(b);
JButton c = new JButton("c. Shift + PP");
p2.add(c);
JButton d = new JButton("d. Alt + P");
p2.add(d);
frame.setVisible(true);
final PopQuizDemo demo = new PopQuizDemo();
a.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
frame.setVisible(false);
demo.randomize();
}
});
b.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
frame.setVisible(false);
demo.randomize();
}
});
c.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
frame.setVisible(false);
demo.randomize();
}
});
d.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
frame.setVisible(false);
demo.randomize();
}
});
}//end of method
}
这里唯一的问题是,当我在“开始”按钮的动作侦听器中调用方法 randomize() 时,它会显示所有帧。是的,它们没有重复,但它同时显示。我不知道问题出在哪里。是随机化,循环,问题的方法吗?有人能帮我吗?请?非常感谢。
PS:这是类 SimpleFrame
import javax.swing.JFrame;
public class SimpleFrame extends JFrame{
public SimpleFrame(){
setSize(400,300);
setTitle("Pop Quiz!");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(null);
setResizable(false);
}
}