Java开发网 - ［求助］这个程序编译出错了

Topic: ［求助］这个程序编译出错了

1.［求助］这个程序编译出错了

Posted by: mitnickcbc
Posted on: 2002-12-13 19:57

import java.awt.*;
import java.awt.event.*;

public class StickyPad implements ActionListener, WindowListener
{
  private Frame frm;
  private TextArea noteTA, responseTA;
  private Button submitBtn, leaveBtn, returnBtn;
  private String savedMessages;

  public StickyPad()
  {
    savedMessages = "";
    frm = new Frame("Sticky Pad");

    Panel centerPnl = new Panel();
    centerPnl.setLayout(new FlowLayout());

    noteTA = new TextArea(6, 40);
    //set the color of the text area to yellow
    noteTA.setBackground(Color.yellow);
    //set the font of the text area to a large 20 point font
    noteTA.setFont(new Font("Dialog", Font.PLAIN, 20));
    centerPnl.add(noteTA);

    responseTA = new TextArea(6, 40);
    //set the color of the text area to green
    responseTA.setBackground(Color.green);
    //set the font of the text area to a large 20 point font
    responseTA.setFont(new Font("Dialog", Font.PLAIN, 20));
    centerPnl.add(responseTA);

    Panel southPnl = new Panel();
    southPnl.setLayout(new FlowLayout());

    submitBtn = new Button("Submit");
    southPnl.add(submitBtn);
    submitBtn.addActionListener(this);
    submitBtn.setEnabled(false);

    leaveBtn = new Button("Leave");
    southPnl.add(leaveBtn);
    leaveBtn.addActionListener(this);

    returnBtn = new Button("Return");
    southPnl.add(returnBtn);
    returnBtn.addActionListener(this);
    returnBtn.setEnabled(false);

    frm.add(centerPnl, BorderLayout.CENTER);
    frm.add(southPnl, BorderLayout.SOUTH);

    frm.setSize(500, 420);
    frm.show();
    frm.addWindowListener(this);
  }//constructor
  public void windowClosing(ActionEvent e)
  {
    System.exit(0);
  }

  public void windowOpened(ActionEvent e) {}
  public void windowClosed(ActionEvent e) {}
  public void windowIconified(ActionEvent e) {}
  public void windowDeiconified(ActionEvent e) {}
  public void windowActivated(ActionEvent e) {}
  public void windowDeactivated(ActionEvent e) {}

  public void actionPerformed(ActionEvent e)
  {
    if (e.getActionCommand().equals("Leave"))
    {
      //Disable the outgoing text area so it can
      //not be changed and enable the response text
      //area and buttons
      noteTA.setEnabled(false);
      leaveBtn.setEnabled(false);
      returnBtn.setEnabled(true);
      submitBtn.setEnabled(true);
    }
    else if (e.getActionCommand().equals("Submit"))
    {
      //Save the message and clear the response text
      //area for the next visitor
      savedMessages += responseTA.getText() + "\n";
      responseTA.setText("");
    }
    else if (e.getActionCommand().equals("Return"))
    {
      //Disable the response text area and buttons and
      //display the save messages
      responseTA.setText(savedMessages);
      submitBtn.setEnabled(false);
      returnBtn.setEnabled(false);
    }
  }
  public static void main(String args[])
  {
    StickyPad sp = new StickyPad();
  }//main
}//class StickyPad

出错信息：
C:\j2sdk1.4.1_01\myprogram\StickyPad.java:4: StickyPad should be declared abstract; it does not define windowOpened(java.awt.event.WindowEvent) in StickyPad
public class StickyPad implements ActionListener, WindowListener
^
1 error

大虾帮忙！

2.Re:［求助］这个程序编译出错了 [Re: mitnickcbc]

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Posted by: Biubiu
Posted on: 2002-12-13 21:17

public void windowOpened(ActionEvent e) {}
public void windowClosed(ActionEvent e) {}
public void windowIconified(ActionEvent e) {}
public void windowDeiconified(ActionEvent e) {}
public void windowActivated(ActionEvent e) {}
public void windowDeactivated(ActionEvent e) {}

Replace ActionEvent with WindowEvent.

Remember to use adater in contrary to listener.

3.Re:［求助］这个程序编译出错了 [Re: mitnickcbc]	Copy to clipboard
Posted by: Biubiu Posted on: 2002-12-13 21:21 By the way, this program is not for j2se1.4. If you compile this class, you should add this method to make j2se1.4 happy. public void windowClosing(WindowEvent e) {}

4.Re:［求助］这个程序编译出错了 [Re: mitnickcbc]	Copy to clipboard
Posted by: mitnickcbc Posted on: 2002-12-13 21:59 对了，谢谢！

5.Re:［求助］这个程序编译出错了 [Re: mitnickcbc]	Copy to clipboard
Posted by: archonLing Posted on: 2002-12-17 14:13 There is another way to do it. You could utilize the abstract class java.awt.event.WindowAdapter to save you some typing . just replace your "WindowListener" with "extends java.awt.event.WindowAdapter" then, you don't have to include all the blank methods for WindowListener interface. Just my 2 cents.