我正在尝试编写我的程序，以便当用户单击“Drive To...”JButton(在我的主类 Dispatch 中)时，它会从用户所在的另一个类 (Cab) 打开一个 JFrame (GoToDistination)可以输入所需的信息，单击“继续”后，它会立即更新 Dispatch JFrame 中的 mainTextArea。
我的问题是，当程序通过主JFrame(Dispatch)时，它只是打开新的JFrame并继续，而不等待输入的信息。它仅在点击开关 JButton 两次后更新(这是因为它切换到 Cab#2，然后返回 Cab#1)。
我对线程进行了一些研究，但我对 Java 仍然是新手，到目前为止我所做的一切都是我自己学到的(这是针对初学者的 Java 大学类(class)，我已经远远超出了这点)。任何有关此问题的可能解决方案的帮助将不胜感激。相关代码如下:
调度类:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.*;
public class Dispatch extends JFrame
{
protected JTextPane mainTextArea;
private JPanel panel;
private JButton GoTo;
private JButton Switch;
private JButton quit;
private Font font;
private int cabNumber=1;
private Cab cab1=new Cab(); //Taxi #1
private Cab cab2=new Cab(); //Taxi #2
public Dispatch()
{
super("Chess City Cab Service"); //Sets the JFrame
Dimension dim= Toolkit.getDefaultToolkit().getScreenSize();
int width=400;
int height=200;
int xWindow=(dim.width-width)/2;
int yWindow=(dim.height-height)/2;
setLocation(xWindow, yWindow);
SimpleAttributeSet bSet = new SimpleAttributeSet(); //For setting JTextPane to Center
StyleConstants.setAlignment(bSet, StyleConstants.ALIGN_CENTER); //Alignment text.
panel=new JPanel();
panel.setBackground(Color.YELLOW);
mainTextArea=new JTextPane(); //create and set JTextPane
mainTextArea.setEditable(false);
font=new Font("Serif",Font.PLAIN, 14);
mainTextArea.setFont(font);
mainTextArea.setBackground(Color.YELLOW);
String cabButtonString="";
menuOutput();
mainTextArea.revalidate();
panel.add(mainTextArea);
StyledDocument doc = mainTextArea.getStyledDocument();
doc.setParagraphAttributes(0, 104, bSet, false);
GoTo=new JButton("Drive To..."); //Tells taxi to go to a certain destination
GoTo.setToolTipText("Click this button to go to a destination");
panel.add(GoTo);
if(cabNumber==1)
cabButtonString="Click this button to switch to cab #2";
else
cabButtonString="Click this button to switch to cab #1";
Switch=new JButton("Switch"); //for switching be/w the two cabs
Switch.setToolTipText(cabButtonString);
panel.add(Switch);
quit=new JButton("Quit"); //quit the program
quit.setToolTipText("Click this button to quit program");
panel.add(quit);
add(panel); //set JFrame size and to visible
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(400,200);
setVisible(true);
HandlerClass handler=new HandlerClass();
GoTo.addActionListener(handler);
Switch.addActionListener(handler);
quit.addActionListener(handler);
}
private class HandlerClass implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
Object source = event.getSource();
if(source==GoTo) //Goes to the GoToDistinationScreen() in the
{ //CabThreadTester Class where user tells the taxi
if (cabNumber==1) //where to go. This is where I need this JFram to pause
{ //and allow for other class to complete before moving on.
cab1.GoToDistinationScreen();
}
else
{
cab2.GoToDistinationScreen();
}
mainTextArea.setText(""); //Clears mainTextArea and then reenters with updated
mainTextArea.revalidate(); //information.
menuOutput();
mainTextArea.revalidate();
}
else if(source==Switch) //Switch between two taxis, currently only way to update taxi location
{ //by pressing twice.
if(cabNumber==1)
{
cabNumber=2;
Switch.setToolTipText("Click this button to switch to cab #1");
Switch.revalidate();
}
else
{
cabNumber=1;
Switch.setToolTipText("Click this button to switch to cab #2");
Switch.revalidate();
}
mainTextArea.setText("");
mainTextArea.revalidate();
menuOutput();
mainTextArea.revalidate();
}
else if(source==quit) //quits the program
{
System.exit(0);
}
}
}
public void menuOutput() //Decides what the mainTextArea will show
{
if(cabNumber==1)
{
mainTextArea.setText(" Cab #"+cabNumber+"\nCurrent Location: Intersection of "+cab1.getAlphaStreetName()+" & "+cab1.getNumericStreetName()+"\nPassenger on board");
}
else
{
mainTextArea.setText(" Cab #"+cabNumber+"\nCurrent Location: Intersection of "+cab2.getAlphaStreetName()+" & "+cab2.getNumericStreetName()+"\nPassenger on board");
}
}
public static void main(String[] args)
{
new Dispatch();
}
}
驾驶室类:
import java.awt.*;
import java.awt.event.*;
import javax.swing.text.*;
import javax.swing.*;
public class Cab
{
public boolean hasPassenger;
private int xLoc, yLoc,xGoTo, yGoTo;
public String alphaStreet;
public String numericStreet;
public Cab()
{
hasPassenger=false;
xLoc=0;
yLoc=0;
xGoTo=0;
yGoTo=0;
alphaStreet="A Street";
numericStreet="Zero Street";
//Sets the initial values
}
public String getAlphaStreetName() //returns alphabetical Street names
{
return alphaStreet;
}
public String getNumericStreetName() //returns numerical street names
{
return numericStreet;
}
public void GoToDistinationScreen() //displays GoToDistination subclass
{
GoToDistination go=new GoToDistination();
go.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
go.setSize(250,175);
go.setVisible(true);
}
public class GoToDistination extends JFrame
{
private JComboBox alphaBox;
private JComboBox numericBox;
private JTextArea goTextArea; //1st textArea
private JTextArea asTextArea; //2nd textArea
private JTextArea nsTextArea; //3rd textArea
private Font font;
private String[] alpha={"A", "B", "C", "D", "E", //both arrays for JComboBox options
"F", "G", "H", "I", "J","K"};
private String[] numeric={"Zero","1st","2nd","3rd","4th","5th","6th","7th",
"8th","9th","10th"};
private JButton Continue, Cancel;
private String letter, number; //Data Stored from ItemEvents
private JPanel panel;
public GoToDistination()
{
super("Chess City Cab Service");
Dimension dim= Toolkit.getDefaultToolkit().getScreenSize();
int width=250; //sets the JFrame
int height=175;
int xWindow=(dim.width-width)/2;
int yWindow=(dim.height-height)/2;
setLocation(xWindow, yWindow);
panel=new JPanel();
panel.setBackground(Color.YELLOW);
goTextArea=new JTextArea(1,20);
goTextArea.setEditable(false);
font=new Font("Serif",Font.PLAIN, 14);
goTextArea.setFont(font); //sets goTextArea
goTextArea.setBackground(Color.YELLOW);
goTextArea.append(" Drive to the intersection of: ");
panel.add(goTextArea);
alphaBox=new JComboBox(alpha);
letter=alphaBox.getSelectedItem().toString(); //for if there is no ItemEvent
alphaBox.addItemListener(
new ItemListener()
{
public void itemStateChanged(ItemEvent event)
{
if(event.getStateChange()==ItemEvent.SELECTED)
letter=alphaBox.getSelectedItem().toString();
}
}
);
panel.add(alphaBox); //sets the asTextArea
asTextArea=new JTextArea(1,5);
asTextArea.append(" Street & ");
asTextArea.setEditable(false);
asTextArea.setFont(font);
asTextArea.setBackground(Color.YELLOW);
panel.add(asTextArea);
numericBox=new JComboBox(numeric);
number=numericBox.getSelectedItem().toString();
numericBox.addItemListener(
new ItemListener()
{
public void itemStateChanged(ItemEvent event) //for if there is no ItemEvent
{
if(event.getStateChange()==ItemEvent.SELECTED)
number=numericBox.getSelectedItem().toString();
}
}
);
panel.add(numericBox);
nsTextArea=new JTextArea(1,4); //sets the nsTextArea
nsTextArea.append(" Street");
nsTextArea.setEditable(false);
nsTextArea.setFont(font);
nsTextArea.setBackground(Color.YELLOW);
panel.add(nsTextArea);
Continue=new JButton("Continue");
Continue.setToolTipText("Click this button to enter selected distination");
panel.add(Continue);
Cancel=new JButton("Cancel");
Continue.setToolTipText("Click this button to cancel actions and return to menu");
panel.add(Cancel);
add(panel);
HandlerClass handler=new HandlerClass();
Continue.addActionListener(handler);
Cancel.addActionListener(handler);
}
private class HandlerClass implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
Object source = event.getSource();
if(source==Continue)
{
int hashletter=letter.hashCode();
int hashnumber=number.hashCode();
xGoTo=aSwitch(hashletter);
yGoTo=nSwitch(hashnumber);
alphaStreet=aStreetName(xGoTo); //sets Street names for the location of taxi
numericStreet=nStreetName(yGoTo);
dispose();
}
else if(source==Cancel)
{
dispose();
}
}
}
private String aStreetName(int xGoTo)
{
switch(xGoTo)
{
case 0:return "A Street";
case 1:return "B Street";
case 2:return "C Street";
case 3:return "D Street";
case 4:return "E Street";
case 5:return "F Street";
case 6:return "G Street";
case 7:return "H Street";
case 8:return "I Street";
case 9:return "J Street";
}
return "K Street";
}
private String nStreetName(int yGoTo)
{
switch(yGoTo)
{
case 0:return "Zero Street";
case 1:return "1st Street";
case 2:return "2nd Street";
case 3:return "3rd Street";
case 4:return "4th Street";
case 5:return "5th Street";
case 6:return "6th Street";
case 7:return "7th Street";
case 8:return "8th Street";
case 9:return "9th Street";
}
return "10th Street";
}
private int aSwitch(int hashletter)
{
switch(hashletter)
{
case 65:return 0;
case 66:return 1;
case 67:return 2;
case 68:return 3;
case 69:return 4;
case 70:return 5;
case 71:return 6;
case 72:return 7;
case 73:return 8;
case 74:return 9;
}
return 10;
/* hash table for alpha string array
A: 65
B: 66
C: 67
D: 68
E: 69
F: 70
G: 71
H: 72
I: 73
J: 74
K: 75
*/
}
private int nSwitch(int hashnumber)
{
switch(hashnumber)
{
case 2781896:return 0;
case 50770:return 1;
case 51560:return 2;
case 52645:return 3;
case 53672:return 4;
case 54633:return 5;
case 55594:return 6;
case 56555:return 7;
case 57516:return 8;
case 58477:return 9;
}
return 10;
/* hash table for numeric string array
Zero: 2781896
1st: 50770
2nd: 51560
3rd: 52645
4th: 53672
5th: 54633
6th: 55594
7th: 56555
8th: 57516
9th: 58477
10th: 1509587
*/
}
}
}
最佳答案
除了不便之外，我不确定 Dispatch 会给聚会带来什么。相反，我会关注单个 Cab 的状态，并根据需要多次复制它。在下面的示例中，Cab 具有可调节的颜色和里程表。 Timer 会定期递增里程表值。每个独立的 Cab 在 JTabbedPane 中占据一个单独的选项卡。
附录:回到问题“如何暂停 main()”，答案是“不要”。相反，使用单独的线程，例如由Timer管理的一个，用于推进模型的状态并更新显示。
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.DecimalFormat;
import java.util.Random;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
import javax.swing.Timer;
/** @see http://stackoverflow.com/questions/5617027 */
public class Cab extends JPanel {
private static final Random random = new Random();
private static final String format = "00000000";
private static final DecimalFormat df = new DecimalFormat(format);
private Hue hue = Hue.Yellow;
private Timer timer;
private JLabel odometer = new JLabel(df.format(0));
private int km;
public Cab() {
this.setPreferredSize(new Dimension(320, 240));
this.setBackground(hue.getColor());
this.add(odometer);
final JComboBox colorBox = new JComboBox();
for (Hue h : Hue.values()) {
colorBox.addItem(h);
}
colorBox.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
Hue h = (Hue) colorBox.getSelectedItem();
Cab.this.setBackground(h.getColor());
}
});
this.add(colorBox);
timer = new Timer(250, new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
km += random.nextInt(100);
odometer.setText(df.format(km));
}
});
timer.start();
}
private enum Hue {
Yellow(Color.yellow), Cyan(Color.cyan), Magenta(Color.magenta);
private final Color color;
private Hue(Color color) {
this.color = color;
}
public Color getColor() {
return color;
}
}
private static void display() {
JFrame f = new JFrame("Dispatch");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JTabbedPane tabbedPane = new JTabbedPane();
tabbedPane.add("Cab #1", new Cab());
tabbedPane.add("Cab #2", new Cab());
tabbedPane.add("Cab #3", new Cab());
f.add(tabbedPane);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
display();
}
});
}
}
关于java - 如何暂停 main()，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/5617027/