APPLET 和 WEB 事件的交互. 文章出处：DIY部落(http://www.diybl.com/course/1_web/webjs/200877/131922.html)

本文介绍了一个简单的Java Applet应用，该应用通过按钮点击改变背景颜色，并能从HTML参数中读取初始状态。此外，还实现了两个额外的功能：通过setParameter方法改变颜色状态并重新绘制界面，以及将两个字符串形式的数字相加并显示结果。

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java 代码如下：

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

public class AppletTest extends JApplet implements ActionListener {
    private static final long serialVersionUID = 1L;
    private String colorOn;
    private boolean val = false;

private String msg = "";
private JButton btn = new JButton("Change Color");

    public void actionPerformed(ActionEvent event) {
        if (event.getSource() == btn) {
            val = !val;
            repaint();
        }
    }

    public void init() {
        Container ct = getContentPane();
        ct.setLayout(new FlowLayout());
        ct.add(btn);
        btn.addActionListener(this);
        msg = getParameter("msg");
        colorOn = getParameter("colorOn");
        if (colorOn.equals("true"))
            val = true;
    }

    public void paint(Graphics g) {
        if (val == true)
            g.setColor(Color.RED);
        else
            g.setColor(Color.BLUE);
        g.drawString(msg, 50, 50);
    }

    public void setParameter(String paramName, String paramValue) {
        if (paramName.equals("colorOn"))
            val = !val;
        repaint();
    }

    public String getMsg() {
        return msg;
    }

    public int add(String firstNum, String secondNum) {
        int result = Integer.parseInt(firstNum) + Integer.parseInt(secondNum);
        JOptionPane.showMessageDialog(this, "" + result);
        return result;
    }

}

.HTML 代码如下：

<APPLET CODE=”AppletTest.class” WIDTH=”300” HEIGHT=”200” name=”byteChart”>
    <param name=”colorOn” value=”sdddd”>
    <param name=msg value=”Parameter from Html”>
</APPLET>
<script>
function ColorOn()
{
    byteChart.setParameter(”colorOn”,”true”);
    byteChart.add(”500”,”82”);
}
</script>
<input type=”button” value=”Set Color” onclick=”ColorOn()”>

文章出处：DIY部落(http://www.diybl.com/course/1_web/webjs/200877/131922.html)