图形用户界面的设计与实现ComboBoxExample

来源：互联网发布：思乐数据技术有限公司编辑：程序博客网时间：2024/06/06 15:39

//ComboBoxExample.java

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;

public class ComboBoxExample
{
public static void main(String[] args)
{
  ComboBoxFrame frame = new ComboBoxFrame();
  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  frame.show();
}
}

class ComboBoxFrame extends JFrame
{
public ComboBoxFrame()
{
setTitle("ComboBoxExample");
setSize(WIDTH, HEIGHT);

  Container contentPane = getContentPane();

  //建立容纳组合框的面板
  jobsPanel = new JPanel();

  //新建组合框
  jobsBox = new JComboBox();
  jobsBox.setEditable(true);;
  jobsBox.addItem("job1");
  jobsBox.addItem("job2");
  jobsBox.addItem("job3");
  jobsBox.addItem("job4");
  jobsBox.addItem("job5");
  jobsBox.addItem("job6");

  //增加事件监听器
  jobsBox.addActionListener(new jobsListener());
  jobsPanel.add(choiceLabel);
  jobsPanel.add(jobsBox);

  //建立容纳文本域的面板
  JPanel textPanel = new JPanel();
  //新建文本域
  myTextField = new JTextField("", 15);
  textPanel.add(choosedLabel, BorderLayout.NORTH);
  textPanel.add(myTextField, BorderLayout.CENTER);

contentPane.add(jobsPanel, BorderLayout.NORTH);
contentPane.add(textPanel, BorderLayout.CENTER);
}

//事件监听器
private class jobsListener
  implements ActionListener
{
  public void actionPerformed(ActionEvent event)
  {
   StringBuffer tempSeletedText = new StringBuffer("");
   Object selectedJob = jobsBox.getSelectedItem();
   String str = (String)selectedJob;
   tempSeletedText.append(str);
   myTextField.setText(tempSeletedText.toString());
  }
}

public static final int WIDTH = 300;
public static final int HEIGHT = 150;
public static final JLabel choosedLabel=new JLabel("Job has been choosed:");
public static final JLabel choiceLabel=new JLabel("Job will be choosed:");

private JTextField myTextField;
private JComboBox jobsBox;
private JPanel jobsPanel;
}