计算机知识.ppt

1、实验九,实验目的: 1掌握Java Applet程序结构和开发过程 2了解Applet运行机制 3学会编写Applet对应的HTML文件，掌握从HTML文件向Applet传递参数的方法。,实验内容,1Java Applet程序开发过程 1）编辑源文件 import java.awt.Graphics; import java.applet.Applet; public class HelloWorld2 extends Applet public void paint(Graphics g) g.setColor(Color.green); g.drawString(Hello World!,

2、25,25); g.drawLine(20,200,20,20); ,2）检查无误后（注意大小写）保存文件，注意文件名为HelloWorld2.java。 3）进入命令行（MS-DOS）方式，运行Java编译器：javac HelloWorld2.java 4）如果输出错误信息，则根据错误信息提示的错误所在行返回编辑器进行修改。如果没有输出任何信息此时会在当前目录中生成HelloWorld2.class文件。 5）键入如下HTML代码：, HelloWorld2 ,6）检查后保存文件。文件名HelloWorld2.html。 7）直接双击这个HTML文件，查看Applet在浏览器中的运行结果。

3、或者是用Appletviewer查看Applet的运行结果：Appletviewer HelloWorld2.html,public void paint(Graphics g)/重写 paint方法在窗体上输出图形 super.paint(g); g.drawImage(image1,x,y,this); public void run()/改写run方法 while(true) x+=10; y+=10; try Thread.sleep(100);/线程挂起100毫秒 catch(Exception e) repaint(); if(x800|y800) x=0; y=0; ,3输入运行

4、下面的两个程序，分析运行结果，进一步理解线程 import java.awt.*; import javax.swing.*; import java.awt.event.*; public class Animation1 extends JFrame Image girl=getToolkit().getImage(10.gif); Image shower=getToolkit().getImage(pic4.jpg); public int x=500,y=10; public int x1=200,y1=10; public static void main(String args)

5、 Animation1 ani = new Animation1(Animation); ani.draw(); ani.draw1(); ,public Animation1(String s) super(s); setBounds(200,200,600,600); addWindowListener(new WindowAdapter() public void windowClosing(WindowEvent e) System.exit(0); ); repaint(); setVisible(true); public void paint(Graphics g) g.draw

6、Image(shower,0,0,600,600,this); g.drawImage(girl,x,y,this); g.drawImage(girl,x1,y1,this); ,void draw() while(true) y+=10; try Thread.sleep(100); catch(Exception e) repaint(); if(y=600)break; void draw1() while(true) y1+=10; try Thread.sleep(100); catch(Exception e) repaint(); if(y1=600)break; ,程序2：

7、import java.awt.*; import javax.swing.*; import java.awt.event.*; public class Animation2 extends JFrame Image girl=getToolkit().getImage(10.gif); Image shower=getToolkit().getImage(pic4.jpg); public int x=500,y=10; public int x1=200,y1=10; JPanel p=new JPanel(); public static void main(String args)

8、 Animation2 ani = new Animation2(Animation); ani.new XX().start(); ani.new YY().start(); ,public Animation(String s) super(s); setBounds(200,200,600,600); addWindowListener(new WindowAdapter() public void windowClosing(WindowEvent e) System.exit(0); ); repaint(); add(p,Center); setVisible(true); public void paint(Graphics g) g.drawImage(shower,0,0,600,600,this); g.drawImage(girl,x,y,this); g.drawImage(girl,x1,y1,this); ,class XX extends Thread public void run() while(true) y+=10; try Thread.sleep(100); catch(Exception e) repaint(); if(y=600)b