exercise13_3.java

一款用java编写的小型数据库管理系统

import java.awt.BorderLayout;
import java.awt.Font;
import java.awt.GraphicsEnvironment;
import java.awt.GridLayout;
import java.awt.event.*;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class Exercise13_3 extends Exercise13{
	   public Exercise13_3(){
		GraphicsEnvironment e =
		  GraphicsEnvironment.getLocalGraphicsEnvironment();
		  String[] fontnames =   e.getAvailableFontFamilyNames();
		  JComboBox jc1=new JComboBox(fontnames);
		    String[] number={"16","17","18","20","25","30","35"};
		  JComboBox jc2=new JComboBox(number);
		  JLabel jl1=new JLabel("Font Name");
		  JLabel jl2=new JLabel("Font Size");
		    JPanel jp=new JPanel();
		    jp.setLayout(new GridLayout(1,4,3,3));
		    jp.add(jl1);
			jp.add(jc1);
			jp.add(jl2);
			jp.add(jc2);
			add(jp,BorderLayout.NORTH);
			///通过匿名内部类得到字体名称
			jc1.addItemListener(new ItemListener(){
				public void itemStateChanged(ItemEvent e) {
					String s = (String)e.getItem();	//直接返回所选择的项
	    		Font font = messagePanel.getFont();
	    	    messagePanel.setFont(new Font(s, font.getStyle(), font.getSize()));
				}
			});
			///通过匿名内部类得到字体的大小
			jc2.addItemListener(new ItemListener(){
				public void itemStateChanged(ItemEvent e){
					String n=(String)e.getItem();//直接返回所选择的项
					Font font=messagePanel.getFont();
					messagePanel.setFont(new Font (font.getName(),font.getStyle(),Integer.parseInt(n)));
				}
			});
		}
	   public static void main(String []a){
		   Exercise13_3 frame=new Exercise13_3();
		   frame.setTitle("Exercise13_3");
		   frame.setSize(200, 200);
		   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		   frame.setVisible(true);
	   }
}