Question

如何在文本框中显示指定的文本文件的内容？？？？

我用fileChooser.showOpenDialog(this);找到一文本文件如何将它的内容显示在文本框tArea=new JTextArea(30,80);中？？？？

我的代码（欢迎修改）
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class reader extends JFrame implements ActionListener{
private JTextArea tArea;
JButton button1,button2;
public reader(){
super("文本阅读器");
Container c=getContentPane();
JPanel panel=new JPanel();
button1=new JButton("打 开");
button1.addActionListener(this);
button2=new JButton("退 出");
button2.addActionListener(this);
c.setLayout(new FlowLayout());
c.add(button1);
c.add(button2);
tArea=new JTextArea(30,80);
tArea.setEditable(false);
JScrollPane scrollPane=new JScrollPane(tArea);
panel.add(scrollPane);
c.add(panel);
}
public void actionPerformed(ActionEvent e){
JFileChooser fileChooser=new JFileChooser();
if(e.getSource()==button1){
fileChooser.showOpenDialog(this);
（此处添加将文本文件的内容显示在文本框中的命令）
}
if(e.getSource()==button2)
System.exit(0);
}
public static void main(String ww[]) {
reader frame=new reader();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(900,700);
frame.setResizable(false);
frame.setVisible(true);
}
}

Answer 1

给楼主一个记事本的源程序。楼主可以参考一下
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.event.*;
import java.util.*; //Date needed
import java.io.PrintWriter;
public class NotePad extends JFrame
{
JTextArea jta;
class newl implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
jta.setText("");
}
}

class openl implements ActionListener
{ public void actionPerformed(ActionEvent e)
{
JFileChooser jf=new JFileChooser();
jf.showOpenDialog(NotePad.this);

}

}
//保存文件的监听
class savel implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
JFileChooser jf = new JFileChooser();
jf.showSaveDialog(NotePad.this);

}
}
//打印的监听 ?
class printl implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
// PrintWriter p = new PrintWriter(NotePad.this);
}
}
//退出记事本的监听
class exitl implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
System.exit(0);//退出
}
}

//拷贝的监听
class copyl implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
jta.copy();
}
}

//粘贴的监听
class pastel implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
jta.paste();
}
}
//剪切的监听
class cutl implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
jta.cut();
}
}
//查找的监听

//添加日期的监听
class datel implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
Date d=new Date();
jta.append(d.toString());
}
}

//构造函数
public NotePad()
{
jta=new JTextArea("",24,40);
JScrollPane jsp=new JScrollPane(jta);
JMenuBar jmb=new JMenuBar();
JMenu mFile=new JMenu("File");
JMenu mEdit=new JMenu("Edit");

JMenuItem mNew=new JMenuItem("New",KeyEvent.VK_N);
mNew.addActionListener(new newl());
mFile.add(mNew);

JMenuItem mOpen=new JMenuItem("Open",KeyEvent.VK_O);
mOpen.addActionListener(new openl());
mFile.add(mOpen);

JMenuItem mSave=new JMenuItem("Save");
mSave.addActionListener(new savel());
mFile.add(mSave);

mFile.addSeparator(); //添加分割线

JMenuItem mPrint = new JMenuItem("Print");
mPrint.addActionListener(new printl());
mFile.add(mPrint);

mFile.addSeparator(); //添加分割线

JMenuItem mExit=new JMenuItem("Exit");
mExit.addActionListener(new exitl());
mFile.add(mExit);
mFile.setMnemonic(KeyEvent.VK_F);

//编辑菜单的子菜单的处理
JMenuItem jmi;
jmi=new JMenuItem("Copy");
jmi.addActionListener(new copyl());
mEdit.add(jmi);

jmi=new JMenuItem("Cut");
jmi.addActionListener(new cutl());
mEdit.add(jmi);

jmi=new JMenuItem("Paste");
jmi.addActionListener(new pastel());
mEdit.add(jmi);

mEdit.addSeparator(); //添加分割线

jmi=new JMenuItem("Find");

mEdit.add(jmi);

jmi=new JMenuItem("FindNext");
mEdit.add(jmi);
mEdit.addSeparator();
jmi=new JMenuItem("Select All");
mEdit.add(jmi);
jmi=new JMenuItem("Date/Time");
jmi.addActionListener(new datel());
mEdit.add(jmi);

jmb.add(mFile);
jmb.add(mEdit);

this.setJMenuBar(jmb);

this.getContentPane().add(jsp);
this.setSize(200,200);
this.setVisible(true);
}
//主函数，程序入口点
public static void main(String s[])
{
new NotePad();
}

}