一个关于jbuilder的问题

Question

jButton1.setToolTipText("Open File");
    jButton2.setIcon(image2);
    jButton2.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jButton2_actionPerformed(e);
      }
    });
    jButton2.setToolTipText("Close File");
    jButton3.setIcon(image3);
    jButton3.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jButton3_actionPerformed(e);
      }
    });
    jButton3.setToolTipText("Help");
    jTextArea1.setLineWrap(true);
    jMenuFileOpen.setText("Open....");
    jMenuFileOpen.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jMenuFileOpen_actionPerformed(e);
      }
    });
    jMenuFileNew.setText("New");
    jMenuFileNew.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jMenuFileNew_actionPerformed(e);
      }
    });
    jMenuFileSave.setText("Save");
    jMenuFileSave.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jMenuFileSave_actionPerformed(e);
      }
    });
    jMenuFileSaveas.setText("Save As...");
    jMenuFileSaveas.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jMenuFileSaveas_actionPerformed(e);
      }
    });
    jMenuEdit.setText("Edit");
    jMenuEditFont.setText("Font....");
    jMenuEditFont.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jMenuEditFont_actionPerformed(e);
      }
    });
    jMenuEditColor.setText("Foreground Color");
    jMenuEditColor.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jMenuEditColor_actionPerformed(e);
      }
    });
    jMenuEditBColor.setText("Background Color");
    jMenuEditBColor.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jMenuEditBColor_actionPerformed(e);
      }
    });
    fontChooser1.setFrame(this);
    fontChooser1.setTitle("选择字体");
    document1=jTextArea1.getDocument();
    document1.addDocumentListener(new javax.swing.event.DocumentListener() {
      public void insertUpdate(DocumentEvent e) {
        document1_insertUpdate(e);
      }
      public void removeUpdate(DocumentEvent e) {
        document1_removeUpdate(e);
      }
      public void changedUpdate(DocumentEvent e) {
        document1_changedUpdate(e);
      }
    });

Answer 1

jMenuEditUndo.setText("Undo");
    jMenuEditUndo.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jMenuEditUndo_actionPerformed(e);
      }
    });
    jMenuEditRedo.setText("Redo");
    jMenuEditRedo.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jMenuEditRedo_actionPerformed(e);
      }
    });
    jMenuEditCopy.setText("Copy");
    jMenuEditCopy.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jMenuEditCopy_actionPerformed(e);
      }
    });
    jMenuEditCut.setText("Cut");
    jMenuEditCut.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jMenuEditCut_actionPerformed(e);
      }
    });
    jMenuEditPaste.setText("Paste");
    jMenuEditSelAll.setText("Select All");
    jMenuEditSelAll.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jMenuEditSelAll_actionPerformed(e);
      }
    });
    jToolBar.add(jButton1);
    jToolBar.add(jButton2);
    jToolBar.add(jButton3);
    jMenuFile.add(jMenuFileNew);
    jMenuFile.add(jMenuFileOpen);
    jMenuFile.add(jMenuFileSave);
    jMenuFile.add(jMenuFileSaveas);
    jMenuFile.addSeparator();
    jMenuFile.add(jMenuFileExit);
    jMenuHelp.add(jMenuHelpAbout);
    jMenuBar1.add(jMenuFile);
    jMenuBar1.add(jMenuEdit);
    jMenuBar1.add(jMenuHelp);
    this.setJMenuBar(jMenuBar1);
    contentPane.add(jToolBar, BorderLayout.NORTH);
    contentPane.add(statusBar, BorderLayout.SOUTH);
    contentPane.add(TextScrollPane, BorderLayout.CENTER);
    TextScrollPane.getViewport().add(jTextArea1, null);
    jMenuEdit.add(jMenuEditUndo);
    jMenuEdit.add(jMenuEditRedo);
    jMenuEdit.add(jMenuEditCopy);
    jMenuEdit.add(jMenuEditCut);
    jMenuEdit.add(jMenuEditPaste);
    jMenuEdit.addSeparator();
    jMenuEdit.add(jMenuEditSelAll);
    jMenuEdit.add(jMenuEditFont);
    jMenuEdit.add(jMenuEditColor);
    jMenuEdit.add(jMenuEditBColor);
    document1 = jTextArea1.getDocument();
  }
  /**File | Exit action performed*/
  public void jMenuFileExit_actionPerformed(ActionEvent e) {
    if (!okToAbandon()) {  return;}
    System.exit(0);
  }
  /**Help | About action performed*/
  public void jMenuHelpAbout_actionPerformed(ActionEvent e) {
    TextEditorFrame_AboutBox dlg = new TextEditorFrame_AboutBox(this);
    Dimension dlgSize = dlg.getPreferredSize();
    Dimension frmSize = getSize();
    Point loc = getLocation();
    dlg.setLocation((frmSize.width - dlgSize.width) / 2 + loc.x, (frmSize.height - dlgSize.height) / 2 + loc.y);
    dlg.setModal(true);
    dlg.show();
  }
  /**Overridden so we can exit when window is closed*/
  protected void processWindowEvent(WindowEvent e) {
    super.processWindowEvent(e);
    if (e.getID() == WindowEvent.WINDOW_CLOSING) {
      jMenuFileExit_actionPerformed(null);
    }
  }  void jMenuFileNew_actionPerformed(ActionEvent e) {
    if(okToAbandon()){
       jTextArea1.setText("");
       currentFileName = null;
       saveNeeded = false;
       updateTitle();
    }  }

Answer 2

void jMenuFileOpen_actionPerformed(ActionEvent e) {
    openFile();
  }  void jButton1_actionPerformed(ActionEvent e) {
    openFile();
  }  void jMenuFileSave_actionPerformed(ActionEvent e) {
    saveFile();
  }  void jButton2_actionPerformed(ActionEvent e) {
    saveFile();
  }  void jMenuFileSaveas_actionPerformed(ActionEvent e) {
    saveAsFile();
  }  void jButton3_actionPerformed(ActionEvent e) {  }  void this_windowClosing(WindowEvent e) {
     if (!okToAbandon()) {  return;}
     System.exit(0);
  }  void jMenuEditFont_actionPerformed(ActionEvent e) {
     fontChooser1.setSelectedFont(jTextArea1.getFont());
    if (fontChooser1.showDialog()) {
       jTextArea1.setFont(fontChooser1.getSelectedFont());
     }
     this.repaint();
     jTextArea1.repaint();
  }  void jMenuEditColor_actionPerformed(ActionEvent e) {
     Color color = JColorChooser.showDialog(this,"Foreground Color",jTextArea1.getForeground());
     if (color != null) {
        jTextArea1.setForeground(color);
      }
      this.repaint();
  }  void jMenuEditBColor_actionPerformed(ActionEvent e) {
      Color color = JColorChooser.showDialog(this,"Background Color",jTextArea1.getBackground());
     if (color != null) {
        jTextArea1.setBackground(color);
      }
      this.repaint();
  }
  void openFile(){
if (!okToAbandon()) {
    return;
}
if(JFileChooser.APPROVE_OPTION== jFileChooser1.showOpenDialog(this)) {
openSelectedFile(jFileChooser1.getSelectedFile().getPath());
}
this.repaint();
}
void openSelectedFile(String fileName){
  try{
    File file = new File(fileName);
    int fileSize = (int)file.length();
int charsReaded = 0;
    FileReader in = new FileReader(file);
    char[] data = new char[fileSize];
    while(in.ready()) {
      charsReaded += in.read(data, charsReaded, fileSize - charsReaded);
    }
    in.close();
    jTextArea1.setText(new String(data, 0, charsReaded));
    this.currentFileName = fileName;
    this.saveNeeded = false;
    statusBar.setText("打开 "+fileName);
    updateTitle();
  }
  catch (IOException e){
      statusBar.setText("Error opening "+fileName);
  }
}
boolean okToAbandon() {
  if (!saveNeeded) {
    return true;
  }
  JTextField txtUserName=new JTextField();
  JPasswordField extPwd=new JPasswordField();
  Object[] msg=new Object[]{new String("请输入用户名"),txtUserName,new String("口令"),extPwd};;
  int value=JOptionPane.showConfirmDialog(this, "保存文件吗？", "文本编辑", JOptionPane.YES_NO_CANCEL_OPTION) ;
  JOptionPane.showConfirmDialog(this,msg, "登陆",JOptionPane. OK_CANCEL_OPTION,JOptionPane.INFORMATION_MESSAGE) ;
switch (value) {
    case JOptionPane.YES_OPTION: return saveFile();
    case JOptionPane.NO_OPTION: return true;
    case JOptionPane.CANCEL_OPTION:
    default: return false;
  }
}
void updateTitle(){
  String title;
  if (currentFileName == null) {
    title = "未命名文件";
  }else {
    title = currentFileName;
  }
  if(saveNeeded == true){
      title = "* "+title;
  }
  title = "文本编辑器- " + title;
  this.setTitle(title);
}
boolean saveFile() {
  if (currentFileName == null) {
    return saveAsFile();
  }
  try{
    File file = new File (currentFileName);
FileWriter out = new FileWriter(file);
    String text = jTextArea1.getText();
    out.write(text);
    out.close();
    this.saveNeeded = false;
    updateTitle();
    return true;
  }
  catch (IOException e) {
    statusBar.setText("存储"+currentFileName+ "出错");
  }
  return false;
}
boolean saveAsFile() {
this.repaint();
  if (JFileChooser.APPROVE_OPTION == jFileChooser1.showSaveDialog(this)){
    currentFileName = jFileChooser1.getSelectedFile().getPath();
    this.repaint();
    return saveFile();
  }
  else {
    this.repaint();
    return false;
  }
}  void document1_changedUpdate(DocumentEvent e) {
     saveNeeded = true;
     updateTitle();  }  void this_ancestorResized(HierarchyEvent e) {  }  void document1_insertUpdate(DocumentEvent e) {
    saveNeeded = true;
updateTitle();  }  void document1_removeUpdate(DocumentEvent e) {
     saveNeeded = true;
updateTitle();  }
  void document1_undoableEditHappened(UndoableEditEvent e) {
       edit.addEdit(e.getEdit()) ;
  }
  void jMenuEditCopy_actionPerformed(ActionEvent e) {
    String selText=jTextArea1.getSelectedText();
    if(selText!=null ){
        StringSelection selection=new StringSelection(selText);
        sysClipboard.setContents(selection,null);
     }
  }  void jMenuEditCut_actionPerformed(ActionEvent e) {
    String selText=jTextArea1.getSelectedText();
          if(selText!=null ){
             StringSelection selection=new StringSelection(selText);
             sysClipboard.setContents(selection,null);
             jTextArea1.replaceSelection(" ");
     }
  }
  void jMenuEditUndo_actionPerformed(ActionEvent e) {
    edit.undo();
  }
  void jMenuEditRedo_actionPerformed(ActionEvent e) { 
    edit.redo();
  }
  void jMenuEdit_focusGained(FocusEvent e) { //这里是控制失效的     boolean selFlag=false;
     if(jTextArea1.getSelectedText() !=null){
         selFlag=true;
     }
     jMenuEditCopy.setEnabled(selFlag) ;
     jMenuEditCut.setEnabled(selFlag) ;
     boolean copyedFlag=false;
     if(sysClipboard.getContents(this)!=null){
         copyedFlag=true;
     }
     jMenuEditPaste.setEnabled(copyedFlag);
     jMenuEditUndo.setEnabled(edit.canUndo());
     jMenuEditRedo.setEnabled(edit.canRedo() );
   }  void jMenuEditSelAll_actionPerformed(ActionEvent e) {
     jTextArea1.selectAll();
  }}

Answer 3

十一个记事本程序 主要就是一些普通的功能 但在edit菜单下
undo redo copy cut paste 选项 出现了一些毛病 按理说没有选中字符
copy cut paste 因该失效的 但却没有还有undo redo 刚开始也应该是灰色的 控制代码如下
void jMenuEdit_focusGained(FocusEvent e) { //这里是控制失效的     boolean selFlag=false;
     if(jTextArea1.getSelectedText() !=null){
         selFlag=true;
     }
     jMenuEditCopy.setEnabled(selFlag) ;
     jMenuEditCut.setEnabled(selFlag) ;
     boolean copyedFlag=false;
     if(sysClipboard.getContents(this)!=null){
         copyedFlag=true;
     }
     jMenuEditPaste.setEnabled(copyedFlag);
     jMenuEditUndo.setEnabled(edit.canUndo());
     jMenuEditRedo.setEnabled(edit.canRedo() );
   }
代码没错 但为什么不行啊