java2实用教程(第三版)第七章课后习题答案(耿祥义)

btn_OK = new Button("提交"); btn_OK.addActionListener(this); ta = new TextArea(5,20);
add(baseBox);
add(btn_OK); add(ta); setBounds(120,125,200,260); setResizable(false); setVisible(true); } public void actionPerformed(ActionEvent e) { String regex = "\\w{1,}@\\w{1,}\56\\w{1,}"; String name = tf1.getText(); String email = tf2.getText(); String pos = tf3.getText(); if(!email.matches(regex)) {
add(btn,BorderLayout.SOUTH); setBounds(100,100,300,200); setVisible(true); }
public void actionPerformed(ActionEvent e) { String s = ta1.getSelectedText(); ta2.append(s);
this.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { dispose();//撤销当前窗口 }
} );
setBounds(100,100,500,80);//设置窗口大小 setResizable(false);//设置窗口大小是否可由用户改变 setVisible(true);//设置窗口的显示状态
boxV1.add(new Label("姓名")); boxV1.add(Box.createVerticalStrut(8)); boxV1.add(new Label("E_mail")); boxV1.add(Box.createVerticalStrut(8)); boxV1.add(new Label("职业")); boxV2 = Box.createVerticalBox(); boxV2.add(tf1); boxV2.add(Box.createVerticalStrut(8)); boxV2.add(tf2); boxV2.add(Box.createVerticalStrut(8)); boxV2.add(tf3); baseBox = Box.createHorizontalBox(); baseBox.add(boxV1); baseBox.add(Box.createHorizontalStrut(10)); baseBox.add(boxV2); setLayout(new FlowLayout());
tf2.setText("非法 E_mail 地址"); } else {
String total = "姓名:" + name + "\nE_mail:" + email + "\n 职 业:" + pos;
ta.append(total); } } }
import java.awt.*; import java.awt.event.*;
} }
//带关闭功能的窗口 import java.awt.*; import javs T7_6 { public static void main(String [] args) { new MathWindow("计算"); }
}
class MathWindow extends Frame implements ActionListener {//定义一 个类继承于 Frame 并实现了接口 ActionListener
}
import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.border.*;
public class T7_7 { public static void main(String [] args) { WindowBox wb = new WindowBox("确定"); }
l1.setText("x"); tf3.setText(String.valueOf(m*n)); } else if(e.getSource() == btn_Mov) { l1.setText("/"); tf3.setText(String.valueOf(1.0*m/n)); } else { System.exit(0); } } catch(NumberFormatException e1) {//异常处理 System.out.println("输入数字字符串!"); } }
public class T7_8 { public static void main(String [] args) { new MyFrame("Panel"); }
} }
import java.awt.*; import java.awt.event.*; public class T7_5 {
public static void main(String [] args) { new MyFrame("挑单词");
} }
class MyFrame extends Frame implements ActionListener { TextArea ta1,ta2; Button btn; MyFrame (String s) { super(s); setLayout(new BorderLayout()); ta1 = new TextArea(5,15); ta2 = new TextArea(5,15); btn = new Button("追加"); btn.addActionListener(this); add(ta1,BorderLayout.EAST); add(ta2,BorderLayout.WEST);
}
class WindowBox extends Frame implements ActionListener { Box baseBox,boxV1,boxV2; TextField tf1,tf2,tf3; Button btn_OK; TextArea ta; WindowBox(String s) { super(s); tf1 = new TextField(12); tf2 = new TextField(12); tf3 = new TextField(12); boxV1 = Box.createVerticalBox();
} }
class FirstWindow extends Frame implements TextListener{ TextArea textA1,textA2; FirstWindow(String s) { setTitle(s); setLayout(new FlowLayout()); textA1 = new TextArea(6,15); textA2 = new TextArea(6,15); add(textA1); add(textA2); textA1.addTextListener(this); setBounds(0,0,300,300); setVisible(true); validate();
validate();//刷新
}
public void actionPerformed(ActionEvent e) {// 实 现 ActionListener 接口的方法
String s1 = tf1.getText(); String s2 = tf2.getText();//获取两个文本框的内容 try {
}
public void textValueChanged(TextEvent e) { String s = textA1.getText(); StringTokenizer fenxi = new StringTokenizer(s," \n\r"); int n = fenxi.countTokens(); long sum=0; try{ for(int i = 0; i<n; i++) { sum += Long.parseLong(fenxi.nextToken()); } textA2.setText("总和" + String.valueOf(sum)); double avg = (double)sum/n; textA2.append("\n 平均数 " + String.valueOf(avg)); } catch (NumberFormatException e1) { //System.out.println("输入有误!"); System.out.println(s); }
long m = Long.parseLong(s1); long n = Long.parseLong(s2);//将获取的文本框的内容转换 成长整型 if(e.getSource() == btn_Add) {//判断事件的发生源 并做 出相应的处理
l1.setText("+"); tf3.setText(String.valueOf(m+n)); } else if(e.getSource() == btn_Sub) { l1.setText("-"); tf3.setText(String.valueOf(m-n)); } else if (e.getSource() == btn_Mul) {