这是我在java Swing中的第一次试用。我遇到的问题是每次月份更改时都会重新创建日历面板。我想在调用addMonth时重新填充panelRightDown（当点击＆gt;或＆lt;时）。我试过在addMonth中调用revalidate，invalidate，repaint但是一切都变得乱七八糟。计算年份时应该采用相同的方法。任何帮助，将不胜感激。更重要的是，我们非常欢迎更好的方法。
public class Gui extends JFrame {
private final int windowWidth = 700;
private final int windowHeight = 600;
private final Container container;
private final JPanel panelLeft = new JPanel();
private final JPanel panelRight = new JPanel();
private final GridBagConstraints gridBagConstraints = new GridBagConstraints();
private final int verticalSpacerSize = 8;
private final int horizontalSpacerSize = 15;
private Border lowerEtchedBorder =
BorderFactory.createEtchedBorder(EtchedBorder.LOWERED);
// -----
protected boolean controlsOnTop;
protected boolean removeOnDaySelection;
protected Calendar currentDisplayDate;
protected JButton prevMonth;
protected JButton nextMonth;
protected JButton prevYear;
protected JButton nextYear;
protected JTextField textField;
protected List<ActionListener> popupListeners =
new ArrayList<ActionListener>();
protected Popup popup;
protected SimpleDateFormat dayName = new SimpleDateFormat("d");
protected SimpleDateFormat monthName = new SimpleDateFormat("MMMM");
protected String iconFile = "datepicker.gif";
protected String[] weekdayNames =
{"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
JPanel datePanel = new JPanel();
JPanel panelRightDown = new JPanel();
JPanel controlsPanel;
// -----
// Constructor to setup the GUI components and event handlers
public Gui() {
//-----
currentDisplayDate = Calendar.getInstance();
controlsOnTop = true;
removeOnDaySelection = true;
//createPanel();
// Retrieve the content-pane of the top-level container JFrame
// All operations done on the content-pane
container = getContentPane();
container.setLayout(new BorderLayout());
//container.setMinimumSize(new Dimension(windowWidth, windowHeight));
createMenuBar();
createStatusBar();
JPanel fullPane = new JPanel();
fullPane.setLayout(new GridBagLayout());
// Spacer
container.add(Box.createVerticalStrut(
4), BorderLayout.NORTH);
container.add(fullPane, BorderLayout.CENTER);
fullPane.setMinimumSize(new Dimension(windowWidth, windowHeight));
// Position Left and Right panels
gridBagConstraints.fill = GridBagConstraints.BOTH;
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 0;
gridBagConstraints.weightx = 0.3;
gridBagConstraints.weighty = 1.0;
fullPane.add(panelLeft, gridBagConstraints);
gridBagConstraints.gridx = 1;
gridBagConstraints.weightx = 0;
fullPane.add(Box.createHorizontalStrut(
15), gridBagConstraints);
gridBagConstraints.fill = GridBagConstraints.BOTH;
gridBagConstraints.gridx = 2;
gridBagConstraints.weightx = 0.9;
fullPane.add(panelRight, gridBagConstraints);
configurePanelLeft(panelLeft);
configurePanelRight(panelRight);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setTitle("Prod - Reminder");
setSize(windowWidth, windowHeight);
setLocationRelativeTo(null);
setVisible(true);
addWindowListener(new Terminator());
}
public void setDate(String date) {
currentDisplayDate = Calendar.getInstance();
editDate(date);
}
public void setDate(Calendar date) {
currentDisplayDate = date;
//createPanel();
validate();
repaint();
}
public void setDate(int month, int day, int year) {
currentDisplayDate = Calendar.getInstance();
currentDisplayDate.set(expandYear(year), month - 1, day);
//createPanel();
validate();
repaint();
}
protected int expandYear(int year) {
if (year < 100) { // 2 digit year
int currentYear = Calendar.getInstance().get(Calendar.YEAR);
int current2DigitYear = currentYear % 100;
int currentCentury = currentYear / 100 * 100;
// set 2 digit year range +20 / -80 from current year
int high2DigitYear = (current2DigitYear + 20) % 100;
if (year <= high2DigitYear) {
year += currentCentury;
}
else {
year += (currentCentury - 100);
}
}
return year;
}
public void setControlsOnTop(boolean flag) {
controlsOnTop = flag;
//createPanel();
repaint();
}
public Calendar getCalendarDate() {
return currentDisplayDate;
}
public Date getDate() {
return currentDisplayDate.getTime();
}
public String getFormattedDate() {
return Integer.toString(getMonth()) + "/" +
Integer.toString(getDay()) + "/" +
Integer.toString(getYear());
}
public int getMonth() {
return currentDisplayDate.get(Calendar.MONTH) + 1;
}
public int getDay() {
return currentDisplayDate.get(Calendar.DAY_OF_MONTH);
}
public int getYear() {
return currentDisplayDate.get(Calendar.YEAR);
}
protected JPanel createControls() {
JPanel c = new JPanel();
c.setBorder(BorderFactory.createRaisedBevelBorder());
c.setFocusable(true);
c.setLayout(new FlowLayout(FlowLayout.CENTER));
prevYear = new JButton("<<");
c.add(prevYear);
prevYear.setMargin(new Insets(0,0,0,0));
prevYear.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
addYear(-1);
}
});
prevMonth = new JButton("<");
c.add(prevMonth);
prevMonth.setMargin(new Insets(0,0,0,0));
prevMonth.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
addMonth(-1);
}
});
textField = new JTextField(getFormattedDate(), 10);
c.add(textField);
textField.setEditable(true);
textField.setEnabled(true);
textField.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
editDate(textField.getText());
}
});
nextMonth = new JButton(">");
c.add(nextMonth);
nextMonth.setMargin(new Insets(0,0,0,0));
nextMonth.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
addMonth(+1);
}
});
nextYear = new JButton(">>");
c.add(nextYear);
nextYear.setMargin(new Insets(0,0,0,0));
nextYear.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
addYear(+1);
}
});
return c;
}
protected JPanel configureDatePicker() {
GridBagLayout gridbag = new GridBagLayout();
GridBagConstraints c = new GridBagConstraints();
datePanel.setFocusable(true);
datePanel.setLayout(gridbag);
String month = monthName.format(currentDisplayDate.getTime());
String year = Integer.toString(getYear());
c.gridx = 0;
c.gridy = 0;
c.gridwidth = 7;
c.gridheight = 1;
JLabel title = new JLabel(month + " " + year);
datePanel.add(title, c);
Font font = title.getFont();
// Font titleFont = new Font(font.getName(), font.getStyle(),
// font.getSize() + 2);
Font weekFont = new Font(font.getName(), font.getStyle(),
font.getSize() - 2);
title.setFont(font);
c.gridy = 1;
c.weightx = 0.1;
c.weighty = 0.1;
c.gridwidth = 1;
c.gridheight = 1;
c.fill = GridBagConstraints.BOTH;
for (c.gridx = 0; c.gridx < 7; c.gridx++) {
JLabel label = new JLabel(
weekdayNames[c.gridx], SwingConstants.CENTER);
datePanel.add(label, c);
label.setFont(weekFont);
}
Calendar draw = (Calendar) currentDisplayDate.clone();
draw.set(Calendar.DATE, 1);
draw.add(Calendar.DATE, -draw.get(Calendar.DAY_OF_WEEK) + 1);
int monthInt = currentDisplayDate.get(Calendar.MONTH);
// monthInt = 0;
// System.out.println("Current month: " + monthInt);
c.gridwidth = 1;
c.gridheight = 1;
int width = getFontMetrics(weekFont).stringWidth(" Wed ");
int width1 = getFontMetrics(weekFont).stringWidth("Wed");
int height = getFontMetrics(weekFont).getHeight() +
(width - width1);
for (c.gridy = 2; c.gridy < 8; c.gridy++) {
for (c.gridx = 0; c.gridx < 7; c.gridx++) {
JButton dayButton;
// System.out.print("Draw month: " + draw.get(Calendar.MONTH));
if (draw.get(Calendar.MONTH) == monthInt) {
String dayString = dayName.format(draw.getTime());
if (draw.get(Calendar.DAY_OF_MONTH) < 10) {
dayString = " " + dayString;
}
dayButton = new JButton(dayString);
} else {
dayButton = new JButton();
dayButton.setEnabled(false);
}
// System.out.println(", day: " + dayName.format(draw.getTime()));
datePanel.add(dayButton, c);
Color color = dayButton.getBackground();
if ((draw.get(Calendar.DAY_OF_MONTH) == getDay()) &&
(draw.get(Calendar.MONTH) == monthInt)) {
dayButton.setBackground(Color.yellow);
// dayButton.setFocusPainted(true);
// dayButton.setSelected(true);
} else
dayButton.setBackground(color);
dayButton.setFont(weekFont);
dayButton.setFocusable(true);
//dayButton.setPreferredSize(new Dimension(width, height));
//dayButton.setMargin(new Insets(0,0,0,0));
dayButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
changeDay(e.getActionCommand());
}
});
//if (dateChange != null)
// dayButton.addActionListener(dateChange);
draw.add(Calendar.DATE, +1);
}
// if (draw.get(Calendar.MONTH) != monthInt) break;
}
return datePanel;
}
public void addMonth(int month) {
currentDisplayDate.add(Calendar.MONTH, month);
datePanel.invalidate();
controlsPanel.invalidate();
panelRightDown.validate();
datePanel = configureDatePicker();
controlsPanel = createControls();
panelRightDown.removeAll();
panelRightDown.add(controlsPanel);
panelRightDown.add(datePanel);
validate();
repaint();
}
public void addYear(int year) {
currentDisplayDate.add(Calendar.YEAR, year);
validate();
repaint();
}
public void editDate(String date) {
parseDate(date);
//createPanel();
validate();
repaint();
}
protected void parseDate(String date) {
String[] parts = date.split("/");
switch (parts.length) {
case 3:
currentDisplayDate.set(Calendar.MONTH,
Integer.valueOf(parts[0]) - 1);
currentDisplayDate.set(Calendar.DAY_OF_MONTH,
Integer.valueOf(parts[1]));
currentDisplayDate.set(Calendar.YEAR,
expandYear(Integer.valueOf(parts[2])));
break;
case 2:
currentDisplayDate = Calendar.getInstance();
currentDisplayDate.set(Calendar.MONTH,
Integer.valueOf(parts[0]) - 1);
currentDisplayDate.set(Calendar.DAY_OF_MONTH,
Integer.valueOf(parts[1]));
break;
default:
// invalid date
currentDisplayDate = Calendar.getInstance();
break;
}
}
public void changeDay(String day) {
currentDisplayDate.set(Calendar.DAY_OF_MONTH,
Integer.valueOf(day.trim()));
textField.setText(getFormattedDate());
if (!removeOnDaySelection) {
//createPanel();
//validate();
repaint();
}
}
private void createMenuBar() {
JMenuBar menubar = new JMenuBar();
JMenu file = new JMenu("File");
file.setMnemonic(KeyEvent.VK_F);
JMenuItem eMenuItem = new JMenuItem("Exit");
eMenuItem.setMnemonic(KeyEvent.VK_E);
eMenuItem.setToolTipText("Exit application");
eMenuItem.addActionListener((ActionEvent event) -> {
System.exit(0);
});
file.add(eMenuItem);
menubar.add(file);
setJMenuBar(menubar);
}
private void createStatusBar() {
// create the status bar panel and shove it down the bottom of the frame
JPanel statusPanel = new JPanel();
statusPanel.setBorder(new BevelBorder(BevelBorder.LOWERED));
container.add(statusPanel, BorderLayout.SOUTH);
statusPanel.setPreferredSize(new Dimension(container.getWidth(), 20));
statusPanel.setLayout(new BoxLayout(statusPanel, BoxLayout.X_AXIS));
JLabel statusLabel = new JLabel("status");
statusLabel.setHorizontalAlignment(SwingConstants.LEFT);
statusPanel.add(statusLabel);
}
public void configurePanelLeft(JPanel panel) {
// Configure Left-side panels
// Top panel
gridBagConstraints.fill = GridBagConstraints.BOTH;
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 0;
gridBagConstraints.weightx = 0.3;
gridBagConstraints.weighty = 0.3;
JPanel panelLeftTop = new JPanel();
panelLeftTop.setBorder(
BorderFactory.createMatteBorder(1, 1, 1, 1, Color.YELLOW));
panel.setLayout(new GridBagLayout());
panel.add(panelLeftTop, gridBagConstraints);
// Display Area
JTextArea displayItem = new JTextArea("Hello, left top!");
displayItem.setBorder(lowerEtchedBorder);
displayItem.setLineWrap(true);
displayItem.setBackground(panel.getBackground());
displayItem.setWrapStyleWord(true);
//displayItem.setEditable(false);
panelLeftTop.setLayout(new BorderLayout());
JScrollPane topScrollPane = new JScrollPane();
topScrollPane.getVerticalScrollBar().setUnitIncrement(3);
topScrollPane.setViewportView(displayItem);
topScrollPane.setHorizontalScrollBarPolicy(
JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
panelLeftTop.add(topScrollPane);
// Spacer
gridBagConstraints.fill = GridBagConstraints.BOTH;
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 1;
gridBagConstraints.weightx = 1.0;
gridBagConstraints.weighty = 0;
panel.add(Box.createVerticalStrut(
verticalSpacerSize), gridBagConstraints);
// Bottom panel
gridBagConstraints.fill = GridBagConstraints.BOTH;
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 2;
gridBagConstraints.weightx = 1.0;
gridBagConstraints.weighty = 0.7;
JPanel panelLeftDown = new JPanel();
panelLeftDown.setBorder(
BorderFactory.createMatteBorder(1, 1, 1, 1, Color.BLUE));
panelLeftDown.setLayout(new GridBagLayout());
for (int i = 0; i < 50; i++) {
gridBagConstraints.fill = GridBagConstraints.BOTH;
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = i;
gridBagConstraints.weightx = 0.3;
//gridBagConstraints.weighty = 1.0;
String textValue = "Area: "+ i
+" This is a very long wrapped text, "
+ "which I expect to be an example of text in a label. "
+ "I really hope it works well."
+ "The Scroll Bar comes when your text goes beyond "
+ "the bounds of your view area. "
+ "Don't use Absolute Positioning, for such a small "
+ "talk at hand, always prefer Layout Managers, "
+ "do read the first para of the first link, "
+ "to know the advantage of using a Layout Manager.";
JTextArea textArea = new JTextArea(textValue);
textArea.setBorder(lowerEtchedBorder);
textArea.setLineWrap(true);
textArea.setBackground(panel.getBackground());
textArea.setWrapStyleWord(true);
textArea.setEditable(false);
textArea.addMouseListener(new MouseListener() {
@Override
public void mouseClicked(MouseEvent e) {
displayItem.setText(textValue);
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
topScrollPane.getVerticalScrollBar().setValue(0);
}
});
}
@Override
public void mousePressed(MouseEvent e) {
//throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
@Override
public void mouseReleased(MouseEvent e) {
//throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
@Override
public void mouseEntered(MouseEvent e) {
//throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
@Override
public void mouseExited(MouseEvent e) {
//throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
});
panelLeftDown.add(textArea, gridBagConstraints);
}
JScrollPane scrollPane = new JScrollPane(panelLeftDown,
JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
panelLeftDown.setAutoscrolls(true);
scrollPane.setPreferredSize(new Dimension(300,800));
scrollPane.getVerticalScrollBar().setUnitIncrement(3);
SwingUtilities.invokeLater(new Runnable() {
public void run() {
scrollPane.getVerticalScrollBar().setValue(0);
}
});
panel.add(scrollPane, gridBagConstraints);
}
public void configurePanelRight(JPanel panel) {
// Configure right-side panels
// Top panel
gridBagConstraints.fill = GridBagConstraints.BOTH;
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 0;
gridBagConstraints.weightx = 1.0;
gridBagConstraints.weighty = 0.1;
JPanel panelRightTop = new JPanel();
panelRightTop.setBorder(
BorderFactory.createMatteBorder(1, 1, 1, 1, Color.YELLOW));
panelRightTop.add(new JLabel("Hello, right top!"));
panel.setLayout(new GridBagLayout());
panel.add(panelRightTop, gridBagConstraints);
// Spacer
gridBagConstraints.fill = GridBagConstraints.BOTH;
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 1;
gridBagConstraints.weightx = 1.0;
gridBagConstraints.weighty = 0;
panel.add(Box.createVerticalStrut(
verticalSpacerSize), gridBagConstraints);
// Bottom panel
gridBagConstraints.fill = GridBagConstraints.BOTH;
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 2;
gridBagConstraints.weightx = 1.0;
gridBagConstraints.weighty = 0.9;
panelRightDown.setBorder(
BorderFactory.createMatteBorder(1, 1, 1, 1, Color.BLUE));
//panelRightDown.add(new JLabel("Hello, right down!"));
panel.add(panelRightDown, gridBagConstraints);
panel.add(panelRightDown, gridBagConstraints);
// Date Picker
gridBagConstraints.fill = GridBagConstraints.BOTH;
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 0;
gridBagConstraints.weightx = 1.0;
gridBagConstraints.weighty = 0.1;
panelRightDown.setLayout(new BorderLayout());
datePanel = configureDatePicker();
controlsPanel = createControls();
panelRightDown.add(controlsPanel, BorderLayout.NORTH);
panelRightDown.add(datePanel, BorderLayout.CENTER);
}
private ListCellRenderer<? super String> getRenderer() {
return new DefaultListCellRenderer(){
@Override
public Component getListCellRendererComponent(JList<?> list,
Object value, int index, boolean isSelected,
boolean cellHasFocus) {
JLabel listCellRendererComponent =
(JLabel) super.getListCellRendererComponent(
list, value, index, isSelected,cellHasFocus);
listCellRendererComponent.setBorder(
lowerEtchedBorder);
listCellRendererComponent.setEnabled(true);
return listCellRendererComponent;
}
};
}
public static void main(String[] args) {
// Run the GUI construction in the Event-Dispatching thread for thread-safety
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new Gui(); // Let the constructor do the job
}
});
}
}