我被困在构建记事本中。问题是，当用户按下清除按钮时，程序会询问用户用户是否确定要清除，如果是，则程序会询问用户是否要在清除之前保存文件，如果是，则保存文件框将打开，但如果否，那么我希望程序清除文本，但是当我按NO时，它与YES按钮相同。有什么建议？请帮忙。
public class NotePad extends JFrame implements ActionListener {
private JTextArea txtArea;
private JMenuBar mnuBar;
private JMenu mnyFile, mnyFormat, mnyEdit, mnyHelp, fontSize;
private JMenuItem openFile, saveFile, exit, textWrap, noTextWrap, font10, font12, font14, font16, font18, font20, clear, copy, cut, paste, abtNotepad;
public NotePad() {
setTitle("NOTEPAD");
setSize(800, 500);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLayout(new BorderLayout());
txtArea = new JTextArea();
JScrollPane scrollArea = new JScrollPane(txtArea);
//MenyBar
mnuBar = new JMenuBar();
mnyFile = new JMenu("File");
mnyFormat = new JMenu("Format");
mnyEdit = new JMenu("Edit");
mnyHelp = new JMenu("Help");
fontSize = new JMenu("Font Size");
openFile = new JMenuItem("Open");
openFile.setAccelerator(KeyStroke.getKeyStroke(
java.awt.event.KeyEvent.VK_O,
java.awt.Event.CTRL_MASK));
saveFile = new JMenuItem("Save");
saveFile.setAccelerator(KeyStroke.getKeyStroke(
java.awt.event.KeyEvent.VK_S,
java.awt.Event.CTRL_MASK));
exit = new JMenuItem("Exit");
exit.setAccelerator(KeyStroke.getKeyStroke(
java.awt.event.KeyEvent.VK_E,
java.awt.Event.CTRL_MASK));
textWrap = new JMenuItem("Text Wrap");
noTextWrap = new JMenuItem("No Text Wrap");
font10 = new JMenuItem("10");
font12 = new JMenuItem("12");
font14 = new JMenuItem("14");
font16 = new JMenuItem("16");
font18 = new JMenuItem("18");
font20 = new JMenuItem("20");
clear = new JMenuItem("Clear");
abtNotepad = new JMenuItem("About Notepad");
copy = new JMenuItem(txtArea.getActionMap().get(DefaultEditorKit.copyAction));
copy.setText("Copy");
copy.setAccelerator(KeyStroke.getKeyStroke(
java.awt.event.KeyEvent.VK_C,
java.awt.Event.CTRL_MASK));
cut = new JMenuItem(txtArea.getActionMap().get(DefaultEditorKit.cutAction));
cut.setText("Cut");
cut.setAccelerator(KeyStroke.getKeyStroke(
java.awt.event.KeyEvent.VK_X,
java.awt.Event.CTRL_MASK));
paste = new JMenuItem(txtArea.getActionMap().get(DefaultEditorKit.pasteAction));
paste.setText("Paste");
paste.setAccelerator(KeyStroke.getKeyStroke(
java.awt.event.KeyEvent.VK_V,
java.awt.Event.CTRL_MASK));
add(mnuBar);
mnuBar.add(mnyFile);
mnuBar.add(mnyFormat);
mnuBar.add(mnyEdit);
mnuBar.add(mnyHelp);
mnyFile.add(openFile);
mnyFile.add(saveFile);
mnyFile.add(exit);
mnyFormat.add(textWrap);
mnyFormat.add(noTextWrap);
mnyFormat.add(fontSize);
mnyEdit.add(clear);
mnyEdit.add(copy);
mnyEdit.add(cut);
mnyEdit.add(paste);
mnyHelp.add(abtNotepad);
fontSize.add(font10);
fontSize.add(font12);
fontSize.add(font14);
fontSize.add(font16);
fontSize.add(font18);
fontSize.add(font20);
exit.addActionListener(this);
openFile.addActionListener(this);
saveFile.addActionListener(this);
clear.addActionListener(this);
abtNotepad.addActionListener(this);
fontSize.addActionListener(this);
font10.addActionListener(this);
font12.addActionListener(this);
font14.addActionListener(this);
font16.addActionListener(this);
font18.addActionListener(this);
font20.addActionListener(this);
textWrap.addActionListener(this);
noTextWrap.addActionListener(this);
setJMenuBar(mnuBar);
add(scrollArea);
setVisible(true);
}
//Main
public static void main(String[] args) {
new NotePad();
}
public void actionPerformed(ActionEvent e) {
if (e.getSource() == this.exit) {
int svar = JOptionPane.showConfirmDialog(null,
"Are you sure you want to quit?", "Exit", JOptionPane.YES_NO_OPTION);
if (svar == JOptionPane.YES_OPTION) {
this.dispose();
}
} else if (e.getSource() == this.openFile) {
JFileChooser open = new JFileChooser();
int option = open.showOpenDialog(this);
if (option == JFileChooser.APPROVE_OPTION) {
this.txtArea.setText("");
try {
Scanner scan = new Scanner(new FileReader(open.getSelectedFile().getPath()));
while (scan.hasNext()) {
this.txtArea.append(scan.nextLine() + "\n");
}
} catch (Exception ex) {
System.out.println(ex.getMessage());
}
}
} else if (e.getSource() == this.saveFile) {
JFileChooser save = new JFileChooser();
int option = save.showSaveDialog(this);
if (option == JFileChooser.APPROVE_OPTION) {
try {
BufferedWriter out = new BufferedWriter(new FileWriter(save.getSelectedFile().getPath()));
out.write(this.txtArea.getText());
out.close();
} catch (Exception ex) {
System.out.println(ex.getMessage());
}
}
} else if (e.getSource() == this.clear) {
int reply = JOptionPane.showConfirmDialog(null,
"Are you sure you want to clear the text ?", "Clear", JOptionPane.YES_NO_OPTION);
if (reply == JOptionPane.YES_OPTION) {
JOptionPane.showConfirmDialog(null,
"Do you want to save your document?", "Save", JOptionPane.YES_NO_OPTION);
if (reply == JOptionPane.YES_OPTION) {
JFileChooser lagre = new JFileChooser();
int options = lagre.showSaveDialog(this);
if (options == JFileChooser.APPROVE_OPTION) {
try {
BufferedWriter ut = new BufferedWriter(new FileWriter(lagre.getSelectedFile().getPath()));
ut.write(this.txtArea.getText());
ut.close();
} catch (Exception x) {
System.out.println(x.getMessage());
}
}
}
} else if (e.getSource() == this.abtNotepad) {
JOptionPane.showMessageDialog(null, "This Application is brought to you by a 1. Year student from Norwegian School of Information Technology."
+ "\n Hope you enjoy it.", "About Notepad", JOptionPane.INFORMATION_MESSAGE);
} else if (e.getSource() == this.font10) {
Font str10 = new Font("Times New Roman", Font.BOLD, 10);
txtArea.setFont(str10);
} else if (e.getSource() == this.font12) {
Font str12 = new Font("Times New Roman", Font.BOLD, 12);
txtArea.setFont(str12);
} else if (e.getSource() == this.font14) {
Font str14 = new Font("Times New Roman", Font.BOLD, 14);
txtArea.setFont(str14);
} else if (e.getSource() == this.font16) {
Font str16 = new Font("Times New Roman", Font.BOLD, 16);
txtArea.setFont(str16);
} else if (e.getSource() == this.font18) {
Font str18 = new Font("Times New Roman", Font.BOLD, 18);
txtArea.setFont(str18);
} else if (e.getSource() == this.font20) {
Font str20 = new Font("Times New Roman", Font.BOLD, 20);
txtArea.setFont(str20);
} else if (e.getSource() == this.textWrap) {
txtArea.setLineWrap(true);
} else if (e.getSource() == this.noTextWrap) {
txtArea.setLineWrap(false);
}
}
}
}
答案 0 :(得分：1)
JOptionPane.showConfirmDialog(null,
"Do you want to save your document?", "Save", OptionPane.YES_NO_OPTION);
此行是您的问题。在if语句中。你实际上并没有再次设置“reply”变量，而是仍在查看第一个JOptionPane中的“reply”变量。将此设置为...
reply = JOptionPane.showConfirmDialog(null,"Do you want to save your document?",
"Save", OptionPane.YES_NO_OPTION);
就像你在第一次迭代中所做的那样。