exercise13.java

一款用java编写的小型数据库管理系统

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;



public class Exercise13 extends JFrame{
	protected MessagePanel messagePanel
    = new MessagePanel("Welcome to Java");
	  private JCheckBox jchkCentered = new JCheckBox("Centered");
	  private JCheckBox jchkBold = new JCheckBox("Bold");
	  private JCheckBox jchkItalic = new JCheckBox("Italic");
   public Exercise13(){
	    jchkCentered.setMnemonic('C');
	    jchkBold.setMnemonic('B');
	    jchkItalic.setMnemonic('I');
	    JPanel jp1=new JPanel();
	    jp1.setLayout(new GridLayout(1, 3));
	    jp1.add(jchkCentered);
	    jp1.add(jchkBold);
	    jp1.add(jchkItalic);
	    add(jp1, BorderLayout.SOUTH );
	    messagePanel.setBackground(Color.yellow);
	    add(messagePanel,BorderLayout.CENTER);
	    jchkCentered.addActionListener(new ActionListener() {
	        public void actionPerformed(ActionEvent e) {
	           messagePanel.setCentered(jchkCentered.isSelected());//直接返回字体是否居中对齐
	        }
	      });
	    ///直接返回messagePanel中的内容是否加粗
	    jchkBold.addActionListener(new ActionListener() {
	        public void actionPerformed(ActionEvent e) {
	           	int fontStyle=Font.PLAIN;
		       		if(jchkBold.isSelected())
	    			 fontStyle=Font.BOLD;
	    		Font font = messagePanel.getFont();
	    	    messagePanel.setFont(new Font(font.getName(), fontStyle, font.getSize()));

	        }
	      });
	    ///直接返回messagePanel中的内容是否斜体
	    jchkItalic.addActionListener(new ActionListener(){
	    	public void actionPerformed(ActionEvent e){
	    		int fontStyle=Font.PLAIN;
	    		if(jchkItalic.isSelected())
	    			fontStyle=Font.ITALIC;
	    		Font font=messagePanel.getFont();
	    		messagePanel.setFont(new Font(font.getName(),fontStyle,font.getSize()));
	    	}
	    });
   }

}