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📁 java课件及例程有一些PPT及一些例程
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例7.2  AppletLife.java的源代码
import java.applet.*;
import java.awt.*;
import javax.swing.*;
//import javax.swing.event.*;
public class AppletLife extends Applet{
     int count;
	public void init()	{
		JOptionPane.showMessageDialog(null,"hello,init方法被调用");
	}
	public void start(){
		JOptionPane.showMessageDialog(null,"回来了,start方法被调用");
	}
	public void stop(){
		JOptionPane.showMessageDialog(null,"欢迎再来,stop方法被调用");
	}
	public void destroy(){
		JOptionPane.showMessageDialog(null,"再见,destroy方法被调用");
	}
	public void paint(Graphics g){
		g.drawString("这是第"+(++count)+"次调用paint()方法",30,30);
	}
}

例7.3 HelloJAppletWorld.java的源代码
import java.awt.Graphics;
import javax.swing.JApplet;	  // 导入JApplet类
public class HelloJAppletWorld extends JApplet{ 	// 继承JApplet类
    public void init(){
        resize(300,100);
    }
    public void paint(Graphics g){
    	super.paint(g);						// 调用父类的方法
        g.drawString("Hello, Welcome to the Java JApplet world!",10,20);
   }
}

例7.4 AppletTest.java的源代码：
import javax.swing.*;
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class AppletTest1 extends JApplet 
						implements ActionListener {
	JTextField tf = new JTextField(6);
	JButton btn  = new JButton("确定");
		JLabel lbl = new JLabel("    请您输入一个数字    ");
		public void init() {
			Container cp=getContentPane();

			cp.add(tf);
			cp.add(btn);
			cp.add(lbl);
			cp.setLayout(new FlowLayout());
			btn.addActionListener(this);
		}
		public void actionPerformed(ActionEvent e) {
			String s = tf.getText();
			double d = 0;
			try {
				d = Double.parseDouble(s);
				double q = d*d*d;
				lbl.setText(d + "的立方是" + q);
			} catch(Exception err) {
				lbl.setText("您的输入有问题！ " + err.toString());
			}
		}
	}

例7.5 ApplicationTest.java的源代码：


import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class ApplicationTest {
	public static void main (String args[]) {
		new MyFrame();
	}
}
class MyFrame extends JFrame implements ActionListener {
	JTextField tf = new JTextField(6);
	JButton btn  = new JButton("确定");
	JLabel lbl = new JLabel("请输入一个数字");
	public MyFrame() {
		super("Application求立方测试程序");	
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setLocation(200, 150);
		setSize(400,100);
		Container cp=getContentPane();
		cp.setLayout(new FlowLayout());
		cp.add(tf);
		cp.add(btn);
		cp.add(lbl);
		btn.addActionListener(this);
		show();
	}
	public void actionPerformed(ActionEvent e) {
		String s = tf.getText();
		double d = 0;
		try {
			d = Double.parseDouble(s);
			double q = d*d*d;
			lbl.setText(d + "的立方是" + q);
		} catch(Exception err) {
			lbl.setText("您的输入有问题！ " +err.toString());
		}
	}
}

例7.6  ParamDemo.java的源代码：
import javax.swing.*;
import java.awt.*;
public class ParamDemo extends JApplet {
	private String s;
	private int x;
	private int y;
	private int mySize;
	private String fontName;
	Font fnt;
	public void init() {
		s=getParameter("string");
		x=Integer.parseInt(getParameter("xp"));
		y=Integer.parseInt(getParameter("yp"));
		fontName=getParameter("font");
		mySize=Integer.parseInt(getParameter("size"));
	    fnt=new Font(fontName,Font.BOLD ,mySize);
	}
	public void paint(Graphics g) {
		g.setFont(fnt);
		g.drawString(s,x,y);
	}
}

<html>
<head>
<title>Applet与HTML之间的参数传递</title>
</head>
<body>
<applet code="ParamDemo.class" width=300 height=200 VIEWASTEXT>
<param name=font value="隶书">
<param name=size value="20">
<param name=string value="我是从HTML网页中来的！">
<param name=xp value="20">
<param name=yp value="50">
</applet>
</body>
</html>

例7.7 MouseTest.java的源代码：
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class MouseTest extends JApplet {
	boolean flag = false;      // true为按下鼠标，false为松开鼠标
	int x = 20;
	int y = 20;
	Container cp;
	public void init() {
		cp= getContentPane();
		cp.addMouseListener(new MouseAdapter() {
			public void mousePressed(MouseEvent e) {
				flag = true;	  // 标识鼠标按键已按下
			}
			public void mouseReleased(MouseEvent e) {
				x = e.getX();  // 取得鼠标指针当前的X坐标
				y = e.getY();
				flag = false;   // 标识鼠标按键已释放
				repaint();
			}
		}); 
		cp.addMouseMotionListener(new MouseMotionAdapter() {
			public void mouseDragged(MouseEvent ee) {
				if (flag) {   // 如果鼠标按下就绘图
					x = ee.getX();
					y = ee.getY();
					repaint();
				} 
			}
		});
	}    // end init()	
	public void paint(Graphics g) {
		super.paint(g);    // 调用父类方法
   		g.drawString("鼠标拖哪儿，我就去哪儿！！！", x, y);
	} 	
}

例7.8 LoadImage.java的源代码：
import javax.swing.*;
import java.awt.*;
public class LoadImage extends JApplet {
	Image pic1;
	ImageIcon pic2;
		public void init() {
		pic1 = getImage(getDocumentBase(),"2.jpg");
		pic2 = new ImageIcon("3.jpg");
	}
	public void paint(Graphics g) {
		g.drawImage(pic1, 20, 20, this);				// 绘制原始大小的图像
		g.drawImage(pic1, 160, 20, 200, 200, this);		// 绘制指定大小的的图像
		pic2.paintIcon(this, g, 20, 180);				// 使用ImageIcon类绘制的图像
	}
}
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