Java從入門到精通閱讀筆記（第4版）13

package com.lzw;

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

import javax.swing.*;

public class CheckBoxTest extends JFrame{
	
	/**
	 * 複選框
	 */
	private static final long serialVersionUID = 1L;
	private JPanel panel1 = new JPanel();
	private JPanel panel2 = new JPanel();
	private JTextArea jt=new JTextArea(3,10);
	private JCheckBox jc1=new JCheckBox("1");
	private JCheckBox jc2=new JCheckBox("2");
	private JCheckBox jc3=new JCheckBox("3");
	public CheckBoxTest(){
		Container c=getContentPane();
		setSize(200,160);
		setVisible(true);
		setTitle("複選框的使用");
		setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
		c.setLayout(new BorderLayout());

		
		c.add(panel1, BorderLayout.NORTH);
		final JScrollPane scrollPane = new JScrollPane(jt);
		panel1.add(scrollPane);


		c.add(panel2, BorderLayout.SOUTH);
		panel2.add(jc1);
		jc1.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				if(jc1.isSelected())
				jt.append("複選框1被選中\n");
			}
		});

		panel2.add(jc2);
		jc2.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				if(jc2.isSelected())
				jt.append("複選框2被選中\n");
			}
		});

		panel2.add(jc3);
		jc3.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				if(jc3.isSelected())
				jt.append("複選框3被選中\n");
			}
		});
	}
	
	public static void main(String[] args) {
		new CheckBoxTest();

	}

}

下拉列表

package com.lzw;

import java.awt.*;

import javax.swing.*;

public class JComboBoxModelTest extends JFrame {
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	JComboBox<String> jc = new JComboBox<>(new MyComboBox());
	JLabel jl = new JLabel("請選擇證件:");
	
	public JComboBoxModelTest() {
		setSize(new Dimension(160, 180));
		setVisible(true);
		setTitle("在窗口中設置下拉列表框");
		setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
		Container cp = getContentPane();
		cp.setLayout(new FlowLayout());
		cp.add(jl);
		cp.add(jc);
	}
	
	public static void main(String[] args) {
		new JComboBoxModelTest();
	}
}

class MyComboBox extends AbstractListModel<String> implements ComboBoxModel<String> {
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	String selecteditem = null;
	String[] test = { "身份證", "軍人證", "學生證", "工作證" };
	
	public String getElementAt(int index) {
		return test[index];
	}
	
	public int getSize() {
		return test.length;
	}
	
	public void setSelectedItem(Object item) {
		selecteditem = (String) item;
	}
	
	public Object getSelectedItem() {
		return selecteditem;
	}
	
	public int getIndex() {
		for (int i = 0; i < test.length; i++) {
			if (test[i].equals(getSelectedItem()))
				return i;
		}
		return 0;
	}
}