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boolean canUndo() ——ÅжÏÄÜ·ñ½øÐг·Ïû²Ù×÷£¬¿ÉÒÔÔò·µ»Øtrue¡£
boolean canRedo() ——ÅжÏÄÜ·ñ½øÐлָ´²Ù×÷£¬¿ÉÒÔÔò·µ»Øtrue¡£
void Undo() ——½øÐг·Ïû²Ù×÷¡£
void Redo() ——½øÐлָ´²Ù×÷¡£
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JTextArea text = new JTextArea();
UndoManager undomg = new UndoManager();
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text.getDocument().addUndoableEditListener(undomg);
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void addUndoableEditListener(UndoableEditListener listener)
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undomg.Undo(); //³·Ïú
undomg.Redo(); //»Ö¸´
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if(undomg.canUndo()) { //³·Ïú
undomg.Undo();
}
if(undomg.canRedo()) { //»Ö¸´
undomg.Redo();
}
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import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.undo.*;
class UndoDemo extends JFrame {
static JTextArea text = new JTextArea();
static JPanel pnl = new JPanel();
static JButton unbtn = new JButton("³·Ïú");
static JButton rebtn = new JButton("»Ö¸´");
static UndoManager undomg = new UndoManager();
UndoDemo() {
super("³·Ïú¡¢»Ö¸´¹¦ÄÜʵÀý");
setVisible(true);
setSize(400,300);
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