记事本上的代码文件如何删除

1、打开需要编辑的记事本文件。

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2、在需要删除的内容前面点一下鼠标左键，然后安装不松，拖动鼠标到需要删除内容的终止位置，松开鼠标左键，如果需要大面积选择，可以先选择起始行，然后按住键盘上的Shift键不松，拖动文件右侧滚动条到终止位置，点一下鼠标左键，即可选中。

3、右键点选中的内容选择删除，或者按键盘上的Backspace键删除。

4、修改完毕，点文件，选择保存或者按CTRL+S保存即可。

高分求完整JAVA语言编的记事本代码

public class NotePad extends JFrame implements ActionListener, ItemListener {

boolean haveCreated = false;

File file = null;

String strtext = "";

int findIndex = 0;

String findStr;

JMenuBar menubar = new JMenuBar();

JMenu meFile = new JMenu(" 文件 ");

JMenu meEdit = new JMenu(" 编辑 ");

JMenu meStyle = new JMenu(" 风格 ");

JMenu meHelp = new JMenu(" 帮助 ");

JMenuItem miCreate = new JMenuItem(" 新建 ");

JMenuItem miOpen = new JMenuItem(" 打开 ");

JMenuItem miSave = new JMenuItem(" 保存 ");

JMenuItem miSaveAs = new JMenuItem(" 另存为 ");

JMenuItem miExit = new JMenuItem(" 退出 ");

JMenuItem miUndo = new JMenuItem(" 撤消 ");

JMenuItem miCut = new JMenuItem(" 剪切 ");

JMenuItem miCopy = new JMenuItem(" 复制 ");

JMenuItem miPaste = new JMenuItem(" 粘贴 ");

JMenuItem miDelete = new JMenuItem(" 删除 ");

JMenuItem miFind = new JMenuItem(" 查找 ");

JMenuItem miNext = new JMenuItem(" 查找下一个 ");

JMenuItem miReplace = new JMenuItem(" 替换 ");

// 右键弹出菜单项

JMenuItem pmUndo = new JMenuItem(" 撤消 ");

JMenuItem pmCut = new JMenuItem(" 剪切 ");

JMenuItem pmCopy = new JMenuItem(" 复制 ");

JMenuItem pmPaste = new JMenuItem(" 粘贴 ");

JMenuItem pmDelete = new JMenuItem(" 删除 ");

JCheckBoxMenuItem miNewLine = new JCheckBoxMenuItem(" 自动换行 ");

JMenu smLookFeel = new JMenu(" 观感 ");

JMenuItem metal = new JMenuItem(" Metal ");

JMenuItem motif = new JMenuItem(" Motif ");

JMenuItem windows = new JMenuItem(" Windows ");

JMenuItem miAbout = new JMenuItem(" 关于 ");

JPopupMenu popupMenu;

JTextArea text = new JTextArea();

public NotePad() {

super(" 我的记事本 ");

// 为便于区分事件源，设定名字

miCreate.setActionCommand(" create ");

miOpen.setActionCommand(" open ");

miSave.setActionCommand(" save ");

miSaveAs.setActionCommand(" saveAs ");

miExit.setActionCommand(" exit ");

miUndo.setActionCommand(" undo ");

miCut.setActionCommand(" cut ");

miCopy.setActionCommand(" copy ");

miPaste.setActionCommand(" paste ");

miDelete.setActionCommand(" delete ");

miFind.setActionCommand(" find ");

miNext.setActionCommand(" next ");

miReplace.setActionCommand(" replace ");

miNewLine.setActionCommand(" newLine ");

miAbout.setActionCommand(" about ");

pmUndo.setActionCommand(" undo ");

pmCut.setActionCommand(" cut ");

pmCopy.setActionCommand(" copy ");

pmPaste.setActionCommand(" paste ");

pmDelete.setActionCommand(" delete ");

this.setSize(500, 500);

this.setLocation(300, 150);

this.setJMenuBar(menubar);

meFile.setFont(new Font(" 宋体 ", Font.BOLD, 15));

meEdit.setFont(new Font(" 宋体 ", Font.BOLD, 15));

meStyle.setFont(new Font(" 宋体 ", Font.BOLD, 15));

meHelp.setFont(new Font(" 宋体 ", Font.BOLD, 15));

menubar.add(meFile);

menubar.add(meEdit);

menubar.add(meStyle);

menubar.add(meHelp);

meFile.add(miCreate);

meFile.add(miOpen);

meFile.add(miSave);

meFile.add(miSaveAs);

meFile.addSeparator();

meFile.add(miExit);

meEdit.add(miUndo);

meEdit.addSeparator();

meEdit.add(miCut);

meEdit.add(miCopy);

meEdit.add(miPaste);

meEdit.add(miDelete);

meEdit.addSeparator();

meEdit.add(miFind);

meEdit.add(miNext);

meEdit.addSeparator();

meEdit.add(miReplace);

meStyle.add(miNewLine);

meStyle.add(smLookFeel);

smLookFeel.add(metal);

smLookFeel.add(motif);

smLookFeel.add(windows);

meHelp.add(miAbout);

// 添加到右键弹出菜单

popupMenu = new JPopupMenu();

popupMenu.add(pmUndo);

popupMenu.addSeparator();

popupMenu.add(pmCut);

popupMenu.add(pmCopy);

popupMenu.add(pmPaste);

popupMenu.add(pmDelete);

// 添加按钮事件监听

meHelp.addActionListener(this);

miCreate.addActionListener(this);

miOpen.addActionListener(this);

miSave.addActionListener(this);

miSaveAs.addActionListener(this);

miExit.addActionListener(this);

miUndo.addActionListener(this);

miCut.addActionListener(this);

miCopy.addActionListener(this);

miPaste.addActionListener(this);

miDelete.addActionListener(this);

miFind.addActionListener(this);

miNext.addActionListener(this);

miReplace.addActionListener(this);

miNewLine.addItemListener(this);

miAbout.addActionListener(this);

metal.addActionListener(this);

motif.addActionListener(this);

windows.addActionListener(this);

// 添加右键按钮事件监听器

pmUndo.addActionListener(this);

pmCut.addActionListener(this);

pmCopy.addActionListener(this);

pmPaste.addActionListener(this);

pmDelete.addActionListener(this);

// 文本区内容没有选中时某些按钮不可用

miCut.setEnabled(false);

miCopy.setEnabled(false);

miDelete.setEnabled(false);

pmCut.setEnabled(false);

pmCopy.setEnabled(false);

pmDelete.setEnabled(false);

JScrollPane scrollPane = new JScrollPane(text);

getContentPane().add(scrollPane, BorderLayout.CENTER);

text.setFont(new Font(" Fixedsys ", Font.TRUETYPE_FONT, 15));

setVisible(true);

// 添加键盘输入监听器

text.addFocusListener(new MyFocusAdapter());

// 添加鼠标监听器，用于激活右键弹出菜单

text.addMouseListener(new MouseAdapter() {

public void mouseReleased(MouseEvent e) {

if (e.isPopupTrigger()) {

popupMenu.show(e.getComponent(), e.getX(), e.getY());

}

}

});

java简单记事本代码

以下代码是一个完整的实现，你只要复制过去就可以了~~

import java.io.*;

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

import javax.swing.event.*;

import javax.*;

import java.awt.*;

import java.awt.event.*;

import java.io.*;

import java.util.*;

import java.text.*;

import javax.swing.*;

import javax.swing.event.*;

import javax.swing.undo.*;

import javax.swing.text.*;

public class Start

{

public static void main(String args[])

{

new TextPad();

}

}

class TextPad extends JFrame implements ActionListener

{

JTextArea jta=new JTextArea("小廖记事本:)",18,52);

JCheckBoxMenuItem mto1=new JCheckBoxMenuItem("自动换行",true);

String ss1=jta.getText();

UndoableEditListener ue=new UndoHander();

UndoManager undo = new UndoManager();

int StartFindPos=0,a=0,b=0;

GridBagConstraints gbc=new GridBagConstraints();

//Dimension dd=new Dimension();

// jta.getDocument().addUndoableEditListener(ue);

public TextPad()

{

//MyMenuListener ml=new MyMenuListener();

//JTextArea jta=new JTextArea("This is my textpad",18,52);

//System.out.println(dd.getHeight());

//System.out.println(dd.getWidth());

//System.out.println(this.getHeight());

//System.out.println(this.getWidth());

//System.out.println("OK");

this.setTitle("一个功能比较齐全的JAVA记事本");

this.setLocation(180,100);

jta.setLineWrap(true);

jta.setWrapStyleWord(true);

JPanel jp=new JPanel();

JScrollPane jsp=new JScrollPane(jta);

jp.add(jsp);

//Rectangle rt=new Rectangle(0,0,this.getWidth(),this.getHeight());

//jsp.setBounds(rt);

//System.out.println(this.getHeight());

//System.out.println(this.getWidth());

JMenu mf=new JMenu("文件(F)");

JMenuItem mtf1=new JMenuItem("新建");

mtf1.addActionListener(this);

JMenuItem mtf2=new JMenuItem("打开");

//mtf2.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O,InputEvent.CTRL_MASK));

mtf2.addActionListener(this);

JMenuItem mtf3=new JMenuItem("保存");

//mtf3.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S,InputEvent.CTRL_MASK));

mtf3.addActionListener(this);

JMenuItem mtf4=new JMenuItem("另存为");

mtf4.addActionListener(this);

JMenuItem mtf5=new JMenuItem("退出");

mtf5.addActionListener(this);

JMenu me=new JMenu("编辑(E)");

JMenuItem mte1=new JMenuItem("撤消");

mte1.addActionListener(this);

jta.getDocument().addUndoableEditListener(ue);

if(undo.canUndo())

{

mte1.setEnabled(false);

}

JMenuItem mte2=new JMenuItem("剪切");

mte2.addActionListener(this);

JMenuItem mte3=new JMenuItem("复制");

mte3.addActionListener(this);

JMenuItem mte4=new JMenuItem("粘贴");

mte4.addActionListener(this);

//JMenuItem mte5=new JMenuItem("删除");

//mte5.addActionListener(this);

JMenuItem mte6=new JMenuItem("查找");

mte6.addActionListener(this);

//JMenuItem mte7=new JMenuItem("查找下一个");

JMenuItem mte8=new JMenuItem("替换");

mte8.addActionListener(this);

//JMenuItem mte9=new JMenuItem("转到");

JMenuItem mte10=new JMenuItem("全选");

mte10.addActionListener(this);

JMenuItem mte11=new JMenuItem("日期/时间");

mte11.addActionListener(this);

JMenu mo=new JMenu("格式(O)");

//JCheckBoxMenuItem mto1=new JCheckBoxMenuItem("自动换行(W)");

mto1.addActionListener(this);

JMenuItem mto2=new JMenuItem("字体");

mto2.addActionListener(this);

JMenu mv=new JMenu("查看(V)");

JMenuItem mtv1=new JMenuItem("状态栏");

mtv1.setEnabled(false);

JMenu mh=new JMenu("帮助(H)");

JMenuItem mth1=new JMenuItem("关于记事本");

mth1.addActionListener(this);

JMenuBar mb=new JMenuBar();

this.addWindowListener(new WindowAdapter()

{

public void windowClosing(WindowEvent e)

{

System.exit(0);

}

}

);

mb.add(mf);

mb.add(me);

mb.add(mo);

mb.add(mv);

mb.add(mh);

this.setJMenuBar(mb);

mf.add(mtf1);

mf.add(mtf2);

mf.add(mtf3);

mf.add(mtf4);

mf.addSeparator();

mf.add(mtf5);

me.add(mte1);

me.addSeparator();

me.add(mte2);

me.add(mte3);

me.add(mte4);

//me.add(mte5);

me.addSeparator();

me.add(mte6);

//me.add(mte7);

me.add(mte8);

//me.add(mte9);

me.addSeparator();

me.add(mte10);

me.add(mte11);

mo.add(mto1);

mo.add(mto2);

mv.add(mtv1);

mh.add(mth1);

this.getContentPane().add(jsp);

this.setSize(600,400);

this.setResizable(true);

this.setVisible(true);

}

public void actionPerformed(ActionEvent e)

{

if(e.getActionCommand().equals("打开"))

{

try

{

Frame f=new Frame();

FileDialog fd=new FileDialog(f,"打开文件",FileDialog.LOAD);

fd.setVisible(true);

String fpath=fd.getDirectory();

String fname=fd.getFile();

BufferedReader br=new BufferedReader(new FileReader(fpath+fname));

jta.setText("");

String s=br.readLine();

while(s!=null)

{

jta.append(s+"\n");

s=br.readLine();

}

br.close();

}

catch(Exception ex)

{

}

}

if(e.getActionCommand().equals("保存"))

{

String fns=null;

Frame f=new Frame("保存");

FileDialog fd=new FileDialog(f,"保存文件",FileDialog.SAVE);

fd.setFile("*.txt");

fd.setVisible(true);

try

{

String savepath=fd.getDirectory();

String savename=fd.getFile();

if(savename!=null)

{

PrintWriter pw=new PrintWriter(new BufferedWriter(new FileWriter(savepath+savename)));

pw.write(jta.getText(),0,jta.getText().length());

pw.flush();

}

}

catch(Exception esave)

{

}

}

if(e.getActionCommand().equals("新建"))

{

jta.setText("");

}

if(e.getActionCommand().equals("另存为"))

{

Frame f=new Frame("保存");

FileDialog fd=new FileDialog(f,"文件另存为",FileDialog.SAVE);

fd.setVisible(true);

try

{

String savepath=fd.getDirectory();

String savename=fd.getFile();

if(savename!=null)

{

PrintWriter pw=new PrintWriter(new BufferedWriter(new FileWriter(savepath+savename)));

pw.write(jta.getText(),0,jta.getText().length());

pw.flush();

}

}

catch(Exception esave)

{

}

}

if(e.getActionCommand().equals("退出"))

{

String ss2=jta.getText();

if(!ss1.equals(ss2))

{

System.out.println("File is changed.");

}

System.exit(0);

}

if(e.getActionCommand().equals("撤消"))

{

try

{

undo.undo();

//System.out.println(undo.canUndo());

}

catch(Exception eundo)

{

}

}

if(e.getActionCommand().equals("剪切"))

{

jta.cut();

}

if(e.getActionCommand().equals("复制"))

{

jta.copy();

}

if(e.getActionCommand().equals("粘贴"))

{

jta.paste();

}

if(e.getActionCommand().equals("删除"))

{

}

if(e.getActionCommand().equals("全选"))

{

jta.selectAll();

}

if(e.getActionCommand().equals("查找"))

{

try

{

final JDialog jd=new JDialog(this,"查找",true);

GridBagLayout gbl=new GridBagLayout();

GridBagConstraints gbc=new GridBagConstraints();

gbc.weightx=0.5;

gbc.weighty=0.5;

gbc.gridwidth=1;

gbc.gridheight=1;

jd.getContentPane().setLayout(gbl);

jd.setSize(380,100);

jd.setResizable(false);

//jd.setDefaultLookAndFeelDecorated(true);

final JTextField jtf=new JTextField(15);

JLabel jlFind=new JLabel("查找内容:");

jd.getContentPane().add(jlFind);

JButton jbFind=new JButton("查找");

jbFind.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent efind)

{

String strA=jta.getText();

String strB=jtf.getText();

if(a=0)

{

a=strA.indexOf(strB,StartFindPos);

b=strB.length();

StartFindPos=a+b;

if(a==-1)

{

JOptionPane.showMessageDialog(null, "没有您要查找的信息", "查找结果",1);

a=0;

StartFindPos=0;

}

jta.select(a,StartFindPos);

}

}

}

);

JButton jbCancel=new JButton("取消");

jbCancel.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent ejb)

{

jd.dispose();

}

}

);

jd.getContentPane().add(jtf);

jd.getContentPane().add(jbFind);

jd.getContentPane().add(jbCancel);

//jd.setResizable(false);

jd.setLocation(240,200);

jd.setDefaultCloseOperation(DISPOSE_ON_CLOSE);

jd.setVisible(true);

}

catch(Exception efind)

{

}

}

if(e.getActionCommand().equals("替换"))

{

final JDialog jd=new JDialog(this,"替换",true);

GridBagLayout gbl=new GridBagLayout();

GridBagConstraints gbc=new GridBagConstraints();

gbc.weightx=1;

gbc.weighty=1;

gbc.gridwidth=1;

gbc.gridheight=1;

JLabel jlFind=new JLabel("查找:");

JLabel jp=new JLabel("替换内容:");

final JTextField jtf=new JTextField(15);

final JTextField jtf1=new JTextField(15);

jd.getContentPane().setLayout(gbl);

jd.setSize(330,150);

jd.setResizable(false);

final JButton jbReplace=new JButton("替换");

final JButton jbReplaceAll=new JButton("替换所有");

final JButton jbCancel=new JButton("取消");

final JButton jbFind=new JButton("查找");

gbc.gridx=0;

gbc.gridy=0;

jd.getContentPane().add(jlFind,gbc);

gbc.gridx=1;

gbc.gridy=0;

jd.getContentPane().add(jtf1,gbc);

gbc.gridx=2;

gbc.gridy=0;

jd.getContentPane().add(jbFind,gbc);

gbc.gridx=0;

gbc.gridy=1;

jd.getContentPane().add(jp,gbc);

gbc.gridx=1;

gbc.gridy=1;

jd.getContentPane().add(jtf,gbc);

gbc.gridx=2;

gbc.gridy=1;

jd.getContentPane().add(jbReplace,gbc);

gbc.gridx=2;

gbc.gridy=2;

jd.getContentPane().add(jbReplaceAll,gbc);

gbc.gridx=2;

gbc.gridy=3;

jd.getContentPane().add(jbCancel,gbc);

jbFind.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent efind)

{

String strA=jta.getText();

String strB=jtf1.getText();

if(a=0)

{

a=strA.indexOf(strB,StartFindPos);

//System.out.println(a+b);

b=strB.length();

StartFindPos=a+b;

if(a==-1)

{

JOptionPane.showMessageDialog(null, "没有您要查找的信息", "查找结果",1);

a=0;

StartFindPos=0;

}

jta.select(a,StartFindPos);

//System.out.println(StartFindPos);

}

}

}

);

jbReplace.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

if(e.getActionCommand().equals("替换"))

{

String strRepleace=jtf.getText();

jta.replaceSelection(strRepleace);

}

}

}

);

jbReplaceAll.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

while(a-1)

{

String strA=jta.getText();

String strB=jtf1.getText();

a=strA.indexOf(strB,StartFindPos);

if(a==-1)

{

break;

}

//System.out.println(a+b);

b=strB.length();

StartFindPos=a+b;

//System.out.println(StartFindPos);

jta.select(a,StartFindPos);

//System.out.println(StartFindPos);

String strRepleaceAll=jtf.getText();

jta.replaceSelection(strRepleaceAll);

StartFindPos=a+b;

}

JOptionPane.showMessageDialog(null, "全部替换完毕", "替换内容",1);

a=0;

StartFindPos=0;

}

}

);

jbCancel.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent ejb)

{

jd.dispose();

}

}

);

jd.setLocation(240,200);

jd.setVisible(true);

jd.setDefaultCloseOperation(DISPOSE_ON_CLOSE);

}

if(e.getActionCommand().equals("日期/时间"))

{

final JDialog jd=new JDialog(this,"插入日期");

JPanel jp1=new JPanel();

jp1.setLayout(new FlowLayout(FlowLayout.LEFT));

final JTextField jtf=new JTextField(10);

JButton jbOK=new JButton("确定");

JButton jbCancel=new JButton("取消");

//Calendar cl=Calendar.getInstance();

//DateFormat df=DateFormat.getInstance();

//String sdate1=df.format(cl.getTime());

//jtf.setText(sdate1);

jp1.add(jtf);

jp1.add(jbOK);

jp1.add(jbCancel);

jd.getContentPane().add(jp1,"North");

JPanel jp2=new JPanel();

jp2.setLayout(new FlowLayout(FlowLayout.LEFT));

final JCheckBox jcb1=new JCheckBox("格式一");

final JCheckBox jcb2=new JCheckBox("格式二");

final JCheckBox jcb3=new JCheckBox("格式三");

jp2.add(jcb1);

jp2.add(jcb2);

jp2.add(jcb3);

jd.getContentPane().add(jp2,"Center");

jd.setSize(220,120);

jd.setResizable(false);

jd.setLocation(240,200);

final SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");

Calendar cl=Calendar.getInstance();

DateFormat df=DateFormat.getInstance();

final String sdate=df.format(cl.getTime());

jcb1.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

if(e.getActionCommand().equals("格式一"))

{

if(jcb1.isSelected())

{

try

{

SimpleDateFormat sdf1=new SimpleDateFormat("yy年MM月dd日");

Date d=sdf.parse(sdate);

jtf.setText(sdf1.format(d));

jcb2.setEnabled(false);

jcb3.setEnabled(false);

}

catch(Exception estyle1)

{

estyle1.printStackTrace();

}

}

else

{

jcb2.setEnabled(true);

jcb3.setEnabled(true);

}

try

{

System.out.println(jta.getLineStartOffset(3));

//System.out.println(jta.getLineOfOffset(346));

}

catch(Exception eee)

{

}

}

}

}

);

jcb2.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

if(e.getActionCommand().equals("格式二"))

{

if(jcb2.isSelected())

{

try

{

SimpleDateFormat sdf1=new SimpleDateFormat("yy/MM/dd");

Date d=sdf.parse(sdate);

jtf.setText(sdf1.format(d));

jcb1.setEnabled(false);

jcb3.setEnabled(false);

}

catch(Exception estyle2)

{

estyle2.printStackTrace();

}

}

else

{

jcb1.setEnabled(true);

jcb3.setEnabled(true);

}

//System.out.println(jcb1.isSelected());

}

}

}

);

jcb3.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

if(e.getActionCommand().equals("格式三"))

{

if(jcb3.isSelected())

{

jtf.setText(sdate);

jcb1.setEnabled(false);

jcb2.setEnabled(false);

}

else

{

jcb1.setEnabled(true);

jcb2.setEnabled(true);

}

//System.out.println(jcb1.isSelected());

}

}

}

);

jbOK.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

if(e.getActionCommand().equals("确定"))

{

int pos=jta.getCaretPosition();

jta.insert(jtf.getText(),pos);

}

}

}

);

jbCancel.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent ejb)

{

jd.dispose();

}

}

);

jd.setVisible(true);

jd.setDefaultCloseOperation(DISPOSE_ON_CLOSE);

}

if(e.getActionCommand().equals("自动换行"))

{

if(mto1.getState())

{

jta.setLineWrap(true);

jta.setWrapStyleWord(true);

}

else

{

jta.setLineWrap(false);

jta.setWrapStyleWord(false);

}

//System.out.println("OK");

}

if(e.getActionCommand().equals("字体"))

{

final JDialog jd=new JDialog(this,"字体设置");

jd.setLocation(240,200);

//final JFrame jfontview=new JFrame();

GridBagLayout gbl=new GridBagLayout();

GridBagConstraints gbc=new GridBagConstraints();

JButton jbOK=new JButton("确定");

JButton jbCancel=new JButton("取消");

JTextField jtf1=new JTextField(6);

final JTextArea jtaview=new JTextArea(4,8);

//jfontview.getContentPane().add(jtaview);

final JTextField jtf2=new JTextField(6);

final JTextField jtf3=new JTextField(3);

JComboBox jcb1=new JComboBox();

final JComboBox jcb2=new JComboBox();

jcb2.addItem("BOLD");

jcb2.addItem("ITALIC");

jcb2.addItem("PLAIN");

//jcb2.addItem("BOLDITALIC");

jcb2.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

jtf2.setText((String)jcb2.getSelectedItem());

}

}

);

final JComboBox jcb3=new JComboBox();

jcb3.addItem("14");

jcb3.addItem("18");

jcb3.addItem("22");

jcb3.addItem("26");

jcb3.addItem("30");

jcb3.addItem("34");

jcb3.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

jtf3.setText((String)jcb3.getSelectedItem());

//jtaview.setText("SS");

// int fontsizeview=Integer.parseInt((String)jcb3.getSelectedItem());

//Font fontview=new Font("字体预览",Font.BOLD,fontsizeview);

//jtaview.setFont(fontview);

//jtaview.setEditable(false);

}

}

);

gbc.gridheight=1;

gbc.gridwidth=1;

//gbc.gridx=1;

//gbc.gridy=0;

gbc.weightx=0.5;

gbc.weighty=0.5;

jd.getContentPane().setLayout(gbl);

//JLabel jl1=new JLabel("预览:");

JLabel jl2=new JLabel("字型:");

JLabel jl3=new JLabel("大小:");

gbc.gridx=0;

gbc.gridy=0;

jd.getContentPane().add(jl2,gbc);

gbc.gridx=2;

gbc.gridy=0;

jd.getContentPane().add(jl3,gbc);

//gbc.gridx=4;

//gbc.gridy=0;

//jd.getContentPane().add(jl3,gbc);

gbc.gridx=0;

gbc.gridy=1;

jd.getContentPane().add(jtf2,gbc);

gbc.gridx=2;

gbc.gridy=1;

jd.getContentPane().add(jtf3,gbc);

//gbc.gridx=4;

// gbc.gridy=1;

//jd.getContentPane().add(jtf3,gbc);

gbc.gridx=0;

gbc.gridy=2;

jd.getContentPane().add(jcb2,gbc);

gbc.gridx=2;

gbc.gridy=2;

jd.getContentPane().add(jcb3,gbc);

//gbc.gridx=4;

//gbc.gridy=2;

//jd.getContentPane().add(jcb3,gbc);

gbc.gridx=4;

gbc.gridy=1;

jd.getContentPane().add(jbOK,gbc);

gbc.gridx=4;

gbc.gridy=2;

jd.getContentPane().add(jbCancel,gbc);

jbOK.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

if(jtf2.getText().equals("PLAIN"))

{

int fontsize=Integer.parseInt(jtf3.getText());

int fontstyle=0;

Font f=new Font("字体设置",fontstyle,fontsize);

jta.setFont(f);

// System.out.println(f.getFont("楷体_GB2312").getFontName());

}

if(jtf2.getText().equals("BOLD"))

{

int fontsize=Integer.parseInt(jtf3.getText());

int fontstyle=1;

Font f=new Font("字体设置",fontstyle,fontsize);

jta.setFont(f);

}

if(jtf2.getText().equals("ITALIC"))

{

int fontsize=Integer.parseInt(jtf3.getText());

int fontstyle=2;

Font f=new Font("字体设置",fontstyle,fontsize);

jta.setFont(f);

}

jd.dispose();

//System.out.println(fontstyle);

}

}

);

jbCancel.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

jd.dispose();

}

}

);

jd.setSize(200,120);

jd.setResizable(false);

jd.setVisible(true);

jd.setDefaultCloseOperation(DISPOSE_ON_CLOSE);

}

if(e.getActionCommand().equals("关于记事本"))

{

JOptionPane jop=new JOptionPane(null,JOptionPane.INFORMATION_MESSAGE);

jop.showMessageDialog(null,"小廖记事本","关于记事本",JOptionPane.OK_OPTION);

//System.out.println("OK");

}

}

class UndoHander implements UndoableEditListener

{

public void undoableEditHappened(UndoableEditEvent eundo)

{

undo.addEdit(eundo.getEdit());

}

}

}

java文本操作 删除文本中的某一行（或一个对象）

你说的不就是一个记事本吗，

//import java packages

import java.awt.*;

import java.awt.event.*;

import java.text.*;

import java.util.*;

import java.io.*;

import javax.swing.undo.*;

import javax.swing.border.*;

import javax.swing.*;

import javax.swing.text.*;

import javax.swing.event.*;

import java.awt.datatransfer.*;

public class Notepad extends JFrame implements ActionListener,DocumentListener{

//定义变量

//菜单

JMenu fileMenu,editMenu,formatMenu,viewMenu,helpMenu;

//"文件"的菜单项

JMenuItem fileMenu_New,fileMenu_Open,fileMenu_Save,fileMenu_SaveAs,fileMenu_PageSetup,fileMenu_Print,fileMenu_Exit;

//"编辑"的菜单项

JMenuItem editMenu_Undo,editMenu_Redo,editMenu_Cut,editMenu_Copy,editMenu_Paste,editMenu_Delete,editMenu_Find,editMenu_FindNext,editMenu_Replace,

editMenu_GoTo,editMenu_SelectAll,editMenu_TimeDate;

//"格式"的菜单项

JCheckBoxMenuItem formatMenu_LineWrap;

JMenu formatMenu_Color;

JMenuItem formatMenu_Font,formatMenu_Color_FgColor,formatMenu_Color_BgColor;

//"查看"的菜单项

JCheckBoxMenuItem viewMenu_Status;

//"帮助"的菜单项

JMenuItem helpMenu_HelpTopics,helpMenu_About;

//文本编辑区域

JTextArea editArea;

//状态栏标签

JLabel statusLabel;

//弹出菜单及菜单项

JPopupMenu popupMenu;

JMenuItem popupMenu_Undo,popupMenu_Redo,popupMenu_Cut,popupMenu_Copy,popupMenu_Paste,popupMenu_Delete,popupMenu_SelectAll;

//系统剪贴板

Toolkit toolKit=Toolkit.getDefaultToolkit();

Clipboard clipBoard=toolKit.getSystemClipboard();

//其它变量

boolean isNewFile=true; //是否新文件(未保存过的)

File currentFile; //当前文件名

String oldValue; //存放编辑区原来的内容，用于比较文本是否有改动

JButton fontOkButton; //字体设置里的"确定"按钮

//工具栏按钮

JButton newButton,openButton,saveButton,saveAsButton,printButton,undoButton,redoButton,

cutButton,copyButton,pasteButton,deleteButton,searchButton,timeButton,fontButton,

boldButton,italicButton,fgcolorButton,bgcolorButton,helpButton;

//创建撤消操作管理器

protected UndoManager undo = new UndoManager();

protected UndoableEditListener undoHandler = new UndoHandler();

//设置编辑区默认字体

protected Font defaultFont=new Font("宋体",Font.PLAIN,12);

//构造函数开始

public Notepad()

{

super("黄斌的记事本");

//获取容器

Container container=getContentPane();

//创建菜单条

JMenuBar menuBar = new JMenuBar();

//创建文件菜单及菜单项并注册事件监听

JMenu fileMenu = new JMenu("文件(F)", true);

fileMenu.setMnemonic('F');

fileMenu_New = new JMenuItem("新建(N)", 'N');

fileMenu_New.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_N, InputEvent.CTRL_MASK));

fileMenu_New.addActionListener(this);

fileMenu_Open = new JMenuItem("打开(O)...", 'O');

fileMenu_Open.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O, InputEvent.CTRL_MASK));

fileMenu_Open.addActionListener(this);

fileMenu_Save = new JMenuItem("保存(S)", 'S');

fileMenu_Save.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S, InputEvent.CTRL_MASK));

fileMenu_Save.addActionListener(this);

fileMenu_SaveAs = new JMenuItem("另存为(A)...", 'A');

fileMenu_SaveAs.addActionListener(this);

fileMenu_PageSetup = new JMenuItem("页面设置(U)...",'U');

fileMenu_PageSetup.addActionListener(this);

fileMenu_Print = new JMenuItem("打印(P)...", 'P');

fileMenu_Print.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_P, InputEvent.CTRL_MASK));

fileMenu_Print.addActionListener(this);

fileMenu_Exit = new JMenuItem("退出(X)",'X');

fileMenu_Exit.addActionListener(this);

//创建编辑菜单及菜单项并注册事件监听

JMenu editMenu = new JMenu("编辑(E)", true);

editMenu.setMnemonic('E');

editMenu.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e){

checkMenuItemEnabled();//设置剪切、复制、粘贴、删除等功能的可用性

}

}

);

editMenu_Undo = new JMenuItem("撤消(U)",'U');

editMenu_Undo.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Z, InputEvent.CTRL_MASK));

editMenu_Undo.addActionListener(this);

editMenu_Undo.setEnabled(false);

editMenu_Redo = new JMenuItem("重做(R)",'R');

editMenu_Redo.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Y,InputEvent.CTRL_MASK));

editMenu_Redo.addActionListener(this);

editMenu_Redo.setEnabled(false);

editMenu_Cut = new JMenuItem("剪切(T)",'T');

editMenu_Cut.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_X, InputEvent.CTRL_MASK));

editMenu_Cut.addActionListener(this);

editMenu_Copy = new JMenuItem("复制(C)",'C');

editMenu_Copy.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_C, InputEvent.CTRL_MASK));

editMenu_Copy.addActionListener(this);

editMenu_Paste = new JMenuItem("粘贴(P)",'P');

editMenu_Paste.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_V, InputEvent.CTRL_MASK));

editMenu_Paste.addActionListener(this);

editMenu_Delete = new JMenuItem("删除(L)",'L');

editMenu_Delete.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_DELETE, 0));

editMenu_Delete.addActionListener(this);

editMenu_Find = new JMenuItem("查找(F)...",'F');

editMenu_Find.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_F, InputEvent.CTRL_MASK));

editMenu_Find.addActionListener(this);

editMenu_FindNext = new JMenuItem("查找下一个(N)",'N');

editMenu_FindNext.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_F3,0));

editMenu_FindNext.addActionListener(this);

editMenu_Replace = new JMenuItem("替换(R)...",'R');

editMenu_Replace.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_H, InputEvent.CTRL_MASK));

editMenu_Replace.addActionListener(this);

editMenu_GoTo = new JMenuItem("转到(G)...",'G');

editMenu_GoTo.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_G, InputEvent.CTRL_MASK));

editMenu_GoTo.addActionListener(this);

editMenu_SelectAll = new JMenuItem("全选",'A');

editMenu_SelectAll.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_A, InputEvent.CTRL_MASK));

editMenu_SelectAll.addActionListener(this);

editMenu_TimeDate = new JMenuItem("时间/日期(D)",'D');

editMenu_TimeDate.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_F5,0));

editMenu_TimeDate.addActionListener(this);

//创建格式菜单及菜单项并注册事件监听

JMenu formatMenu = new JMenu("格式(O)", true);

formatMenu.setMnemonic('O');

formatMenu_LineWrap = new JCheckBoxMenuItem("自动换行(W)");

formatMenu_LineWrap.setMnemonic('W');

formatMenu_LineWrap.setState(true);

formatMenu_LineWrap.addActionListener(this);

formatMenu_Font = new JMenuItem("字体(F)...",'F');

formatMenu_Font.addActionListener(this);

formatMenu_Color = new JMenu("设置颜色");

formatMenu_Color_FgColor=new JMenuItem("字体颜色");

formatMenu_Color_FgColor.addActionListener(this);

formatMenu_Color_BgColor=new JMenuItem("背景颜色");

formatMenu_Color_BgColor.addActionListener(this);

//创建查看菜单及菜单项并注册事件监听

JMenu viewMenu = new JMenu("查看(V)", true);

viewMenu.setMnemonic('V');

viewMenu_Status = new JCheckBoxMenuItem("状态栏(S)");

viewMenu_Status.setMnemonic('S');

viewMenu_Status.setState(true);

viewMenu_Status.addActionListener(this);

//创建帮助菜单及菜单项并注册事件监听

JMenu helpMenu = new JMenu("帮助(H)", true);

helpMenu.setMnemonic('H');

helpMenu_HelpTopics = new JMenuItem("帮助主题(H)",'H');

helpMenu_HelpTopics.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_F1,0));

helpMenu_HelpTopics.addActionListener(this);

helpMenu_About = new JMenuItem("关于记事本(A)",'A');

helpMenu_About.addActionListener(this);

//向菜单条添加"文件"菜单及菜单项

menuBar.add(fileMenu);

fileMenu.add(fileMenu_New);

fileMenu.add(fileMenu_Open);

fileMenu.add(fileMenu_Save);

fileMenu.add(fileMenu_SaveAs);

fileMenu.addSeparator(); //分隔线

fileMenu.add(fileMenu_PageSetup);

fileMenu.add(fileMenu_Print);

fileMenu.addSeparator(); //分隔线

fileMenu.add(fileMenu_Exit);

//向菜单条添加"编辑"菜单及菜单项

menuBar.add(editMenu);

editMenu.add(editMenu_Undo);

editMenu.add(editMenu_Redo);

editMenu.addSeparator(); //分隔线

editMenu.add(editMenu_Cut);

editMenu.add(editMenu_Copy);

editMenu.add(editMenu_Paste);

editMenu.add(editMenu_Delete);

editMenu.addSeparator(); //分隔线

editMenu.add(editMenu_Find);

editMenu.add(editMenu_FindNext);

editMenu.add(editMenu_Replace);

editMenu.add(editMenu_GoTo);

editMenu.addSeparator(); //分隔线

editMenu.add(editMenu_SelectAll);

editMenu.add(editMenu_TimeDate);

//向菜单条添加"格式"菜单及菜单项

menuBar.add(formatMenu);

formatMenu.add(formatMenu_LineWrap);

formatMenu.add(formatMenu_Font);

formatMenu.addSeparator();

formatMenu.add(formatMenu_Color);

formatMenu_Color.add(formatMenu_Color_FgColor);

formatMenu_Color.add(formatMenu_Color_BgColor);

//向菜单条添加"查看"菜单及菜单项

menuBar.add(viewMenu);

viewMenu.add(viewMenu_Status);

//向菜单条添加"帮助"菜单及菜单项

menuBar.add(helpMenu);

helpMenu.add(helpMenu_HelpTopics);

helpMenu.addSeparator();

helpMenu.add(helpMenu_About);

//向窗口添加菜单条

this.setJMenuBar(menuBar);

//创建文本编辑区并添加滚动条

editArea=new JTextArea(20,50);

JScrollPane scroller=new JScrollPane(editArea);

scroller.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);

container.add(scroller,BorderLayout.CENTER);//向容器添加文本编辑区

editArea.setWrapStyleWord(true); //设置单词在一行不足容纳时换行

editArea.setLineWrap(true); //设置文本编辑区自动换行默认为true,即会"自动换行"

editArea.setFont(defaultFont); //设置编辑区默认字体

editArea.setBackground(Color.white); //设置编辑区默认背景色

editArea.setForeground(Color.black); //设置编辑区默认前景色

oldValue=editArea.getText(); //获取原文本编辑区的内容

//编辑区注册事件监听

editArea.getDocument().addUndoableEditListener(undoHandler);

editArea.getDocument().addDocumentListener(this);

//创建右键弹出菜单

popupMenu=new JPopupMenu();

popupMenu_Undo=new JMenuItem("撤消(U)",'U');

popupMenu_Redo=new JMenuItem("重做(R)",'R');

popupMenu_Cut =new JMenuItem("剪切(T)",'T');

popupMenu_Copy=new JMenuItem("复制(C)",'C');

popupMenu_Paste=new JMenuItem("粘贴(P)",'P');

popupMenu_Delete=new JMenuItem("删除(D)",'D');

popupMenu_SelectAll=new JMenuItem("全选(A)",'A');

popupMenu_Undo.setEnabled(false); //撤消选项初始设为不可用

popupMenu_Redo.setEnabled(false); //重做选项初始设为不可用

//向右键菜单添加菜单项和分隔符

popupMenu.add(popupMenu_Undo);

popupMenu.add(popupMenu_Redo);

popupMenu.addSeparator();

popupMenu.add(popupMenu_Cut);

popupMenu.add(popupMenu_Copy);

popupMenu.add(popupMenu_Paste);

popupMenu.add(popupMenu_Delete);

popupMenu.addSeparator();

popupMenu.add(popupMenu_SelectAll);

//右键菜单注册事件

popupMenu_Undo.addActionListener(this);

popupMenu_Redo.addActionListener(this);

popupMenu_Cut.addActionListener(this);

popupMenu_Copy.addActionListener(this);

popupMenu_Paste.addActionListener(this);

popupMenu_Delete.addActionListener(this);

popupMenu_SelectAll.addActionListener(this);

//文本编辑区注册右键菜单事件

editArea.addMouseListener(

new MouseAdapter(){

public void mousePressed(MouseEvent e)

{

checkForTriggerEvent(e);

}

public void mouseReleased(MouseEvent e)

{

checkForTriggerEvent(e);

}

private void checkForTriggerEvent(MouseEvent e)

{

if(e.isPopupTrigger())

popupMenu.show(e.getComponent(),e.getX(),e.getY());

checkMenuItemEnabled(); //设置剪切、复制、粘贴、删除等功能的可用性

editArea.requestFocus(); //编辑区获取焦点

}

});

//创建工具栏

JPanel toolBar=new JPanel();

toolBar.setLayout(new FlowLayout(FlowLayout.LEFT));

Icon newIcon=new ImageIcon("Icons/new.gif");

Icon openIcon=new ImageIcon("Icons/open.gif");

Icon saveIcon=new ImageIcon("Icons/save.gif");

Icon saveAsIcon=new ImageIcon("Icons/saveas.gif");

Icon printIcon=new ImageIcon("Icons/print.gif");

Icon undoIcon=new ImageIcon("Icons/undo.gif");

Icon redoIcon=new ImageIcon("Icons/redo.gif");

Icon cutIcon=new ImageIcon("Icons/cut.gif");

Icon copyIcon=new ImageIcon("Icons/copy.gif");

Icon pasteIcon=new ImageIcon("Icons/paste.gif");

Icon deleteIcon=new ImageIcon("Icons/delete.gif");

Icon searchIcon=new ImageIcon("Icons/search.gif");

Icon timeIcon=new ImageIcon("Icons/time.gif");

Icon fontIcon=new ImageIcon("Icons/font.gif");

Icon boldIcon=new ImageIcon("Icons/bold.gif");

Icon italicIcon=new ImageIcon("Icons/italic.gif");

Icon bgcolorIcon=new ImageIcon("Icons/bgcolor.gif");

Icon fgcolorIcon=new ImageIcon("Icons/fgcolor.gif");

Icon helpIcon=new ImageIcon("Icons/help.gif");

newButton= new JButton(newIcon);

openButton=new JButton(openIcon);

saveButton= new JButton(saveIcon);

saveAsButton=new JButton(saveAsIcon);

printButton=new JButton(printIcon);

undoButton=new JButton(undoIcon);

undoButton.setEnabled(false);

redoButton=new JButton(redoIcon);

redoButton.setEnabled(false);

cutButton=new JButton(cutIcon);

cutButton.setEnabled(false);

copyButton=new JButton(copyIcon);

copyButton.setEnabled(false);

pasteButton=new JButton(pasteIcon);

pasteButton.setEnabled(false);

deleteButton=new JButton(deleteIcon);

deleteButton.setEnabled(false);

searchButton=new JButton(searchIcon);

timeButton=new JButton(timeIcon);

fontButton=new JButton(fontIcon);

boldButton=new JButton(boldIcon);

italicButton=new JButton(italicIcon);

fgcolorButton=new JButton(fgcolorIcon);

bgcolorButton=new JButton(bgcolorIcon);

helpButton=new JButton(helpIcon);

newButton.setPreferredSize(new Dimension(22,22));

openButton.setPreferredSize(new Dimension(22,22));

saveButton.setPreferredSize(new Dimension(22,22));

saveAsButton.setPreferredSize(new Dimension(22,22));

printButton.setPreferredSize(new Dimension(22,22));

undoButton.setPreferredSize(new Dimension(22,22));

redoButton.setPreferredSize(new Dimension(22,22));

cutButton.setPreferredSize(new Dimension(22,22));

copyButton.setPreferredSize(new Dimension(22,22));

pasteButton.setPreferredSize(new Dimension(22,22));

deleteButton.setPreferredSize(new Dimension(22,22));

searchButton.setPreferredSize(new Dimension(22,22));

timeButton.setPreferredSize(new Dimension(22,22));

fontButton.setPreferredSize(new Dimension(22,22));

boldButton.setPreferredSize(new Dimension(22,22));

italicButton.setPreferredSize(new Dimension(22,22));

fgcolorButton.setPreferredSize(new Dimension(22,22));

bgcolorButton.setPreferredSize(new Dimension(22,22));

helpButton.setPreferredSize(new Dimension(22,22));

//注册工具栏按钮事件

newButton.addActionListener(this);

openButton.addActionListener(this);

saveButton.addActionListener(this);

saveAsButton.addActionListener(this);

printButton.addActionListener(this);

undoButton.addActionListener(this);

redoButton.addActionListener(this);

cutButton.addActionListener(this);

copyButton.addActionListener(this);

pasteButton.addActionListener(this);

deleteButton.addActionListener(this);

searchButton.addActionListener(this);

timeButton.addActionListener(this);

fontButton.addActionListener(this);

boldButton.addActionListener(this);

italicButton.addActionListener(this);

fgcolorButton.addActionListener(this);

bgcolorButton.addActionListener(this);

helpButton.addActionListener(this);

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