jpaneltest.java

详细讲解了java的基础知识

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

public class JPanelTest extends JApplet {
  Panel panel1 = new Panel();
  BorderLayout borderLayout1 = new BorderLayout();
  JButton jButton1 = new JButton(); 
  JButton jButton2 = new JButton();
 JTextField jTextField1 = new JTextField();
  Font ft1,ft2;
  private Component glassPane = new MyGlassPane();

  //初始化
  public void init() {
    try  {
      myInit();
    }
    catch(Exception e)  {   //异常处理
      e.printStackTrace();
    }
  }
 	
 //*************初始设定*******************
  private void myInit() throws Exception {

    this.setGlassPane(glassPane);//将一个JPanel当作一个glassPane	
	
    this.getContentPane().setLayout(borderLayout1);//设定ContentPane的Layout
    //#设定jButton1的外观
    jButton1.setBackground(Color.black);
    jButton1.setForeground(Color.orange);
    ft1=new Font("宋体",Font.BOLD,18);
    jButton1.setFont(ft1);
    jButton1.setText("按钮一");

    //#设定jButton2的外观
    jButton2.setBackground(Color.blue);
    jButton2.setForeground(Color.red);
    ft2=new Font("宋体",Font.PLAIN,18);
    jButton2.setFont(ft2);
    jButton2.setText("按钮二");
    jTextField1.setText("请压一下按钮");
 

    //*****加入组件*****
    this.getContentPane().add(panel1, BorderLayout.SOUTH);
                               //加panel1到ContentPane的南边
    panel1.add(jButton1, null);//Panel加入JButton1
    panel1.add(jButton2, null);//Panel加入JButton2
    this.getContentPane().add(jTextField1, BorderLayout.NORTH);
                               //加TextField1到ContentPane的北边?



    //#Button1的事件倾听#
    jButton1.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jButton1_actionPerformed(e);

      }
    });

    //#Button2的事件倾听#
    jButton2.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jButton2_actionPerformed(e);
      }
    });
   

  }
  //#jButton1的按钮事件#
  void jButton1_actionPerformed(ActionEvent e) {
	  
			glassPane.setVisible(true);
  }
  //#jButton2的按钮事件#
  void jButton2_actionPerformed(ActionEvent e) {
			glassPane.setVisible(false);
  }
 
  //*************初始设定*******************
  

  }
//此类继承JPanel当作glassPane
class MyGlassPane extends JPanel {
	private JButton button;
	private Point point= new Point(100,100),//绘图起始点
				previous,now;//
	private String demoString ="JPanel作GlassPane，可设定DoubleBuffered()";
	
	public MyGlassPane() {
		this.setDoubleBuffered(true);
		this.setOpaque(false);  
		addMouseListener(new MouseAdapter() {
			public void mousePressed(MouseEvent e) {
				previous= e.getPoint();
			}
			
		});
		addMouseMotionListener(new MouseMotionAdapter() {
			public void mouseDragged(MouseEvent e) {
				now= e.getPoint();
				point.x += now.x - previous.x;
				point.y += now.y - previous.y;
				repaint();
				previous.x = now.x;
				previous.y = now.y;
			}
		});
	}
	public void paintComponent(Graphics g) {
		FontMetrics fm = g.getFontMetrics();
		int dsw = fm.stringWidth(demoString);//取得字符串长度
		int dsh = fm.getHeight( );
		int fmAscent = fm.getAscent();
		g.drawRect(point.x, point.y, dsw + 15, dsh + 15);
		g.drawString(demoString,point.x + 5, point.y + fmAscent + 5);
		for(int i=50;i<=150;i+=10){
		g.fillOval(point.x+i, point.y+i,30,30);} 
          
	}
}