Java语言程序设计习题答案(清华大学出版杜)张思民版-1-12章答案(8)

class DiaObj implements ActionListener { Frame fr=new Frame();

TextArea txtAr2=new TextArea(8,10); TextField txtFl=new TextField(20);

Button btnSend=new Button(\发送文字\ Dialog dia;

//初始化DiaObj,并定义参数fr,txtAr2 public DiaObj(Frame fr,TextArea txtAr2){ this.txtAr2=txtAr2; this.fr=fr; dia=new Dialog(fr,\传递消息对话框..\ dia.setSize(200,100); dia.setLayout(new FlowLayout()); dia.add(txtFl); dia.add(btnSend); btnSend.addActionListener(this); dia.addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent we){ dia.setVisible(false); //退出对话框 }} ); dia.validate(); dia.setVisible(true); }

public void actionPerformed(ActionEvent e){ txtAr2.append(txtFl.getText()+\ txtFl.setText(\清空内容 } }

第5章 Java swing基础

【1】 应用swing 组件，改写【例4-4】的密码验证程序。 [解答]：

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

import java.awt.event.*;

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public class XitiDaan5_1 extends JFrame implements ActionListener{ JLabel jl;

JTextField jt2; JPanel jp; TextField t1; JButton jb; XitiDaan5_1(){

super(\密码验证\ setSize(800,600); setVisible(true);

Container con=getContentPane(); con.setLayout(new BorderLayout()); jp=new JPanel();

jl=new JLabel(\请输入密码：\ t1=new TextField(25); t1.setEchoChar('*'); jt2=new JTextField(25); jb=new JButton(\确定\ jp.add(jl); jp.add(t1); jp.add(jb); jp.add(jt2);

con.add(jp,BorderLayout.CENTER); jb.addActionListener(this); validate(); }

public void actionPerformed(ActionEvent e){ if(t1.getText().equals(\ jt2.setText(\密码正确！！\ else

jt2.setText(\密码错误！！\ }

public static void main(String[] args){ new XitiDaan5_1(); } }

程序运行结果如图5.1所示。

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图5.1

【2】将通讯录显示到一个表格中。 [解答]：

// 将通讯录显示到表格 import javax.swing.*; import java.awt.*;

import java.awt.event.*;

class Tongxunlu_Table extends JFrame {

public Tongxunlu_Table() {

super(\班级通讯录\

String[] columnNames = {\姓名\性别\班级\固定电话\手机\地址\ Object[][] data = {

{\张 三\男\泉州\ {\李 四\男\南安\ {\王 五\男\泉州\ {\张 也\女\福州\ {\李 名\男\泉州\ {\张 涛\男\厦门\ {\章 萍\女\泉州\ {\谢少福\男\漳州\ {\黄志强\男\泉州\ {\张志晨\男\龙岩\ {\张明美\女\莆田\ };

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JTable table = new JTable(data,columnNames);

table.setPreferredScrollableViewportSize(new Dimension(500,70)); JScrollPane scrollPane = new JScrollPane(table);

getContentPane().add(scrollPane, BorderLayout.CENTER); addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }); pack();

setSize(800,600); setVisible(true); } }

//主类

public class Xitidaan5_2 {

public static void main(String[] args) {

Tongxunlu_Table frame = new Tongxunlu_Table(); } }

程序运行结果如图5.2所示。

图5.2

【3】 改进【例5-11】，编写一个能动态改变树结点的程序。 [解答]：

/* \利用TreeNode构造动态树\import javax.swing.*; import javax.swing.tree.*; import java.awt.*;

import java.awt.event.*;

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import java.awt.GridLayout; import java.awt.Toolkit; import javax.swing.JLabel; import javax.swing.JPanel;

import javax.swing.JRadioButton; import javax.swing.JScrollPane; import javax.swing.JTree;

import javax.swing.tree.DefaultMutableTreeNode; import javax.swing.tree.DefaultTreeModel; import javax.swing.tree.MutableTreeNode; import javax.swing.tree.TreePath;

import javax.swing.tree.TreeSelectionModel; import javax.swing.event.TreeModelEvent; import javax.swing.event.TreeModelListener;

class TreeNodeChild extends DefaultMutableTreeNode{ JPanel Parent ;

JRadioButton PartRadio ; JLabel PartLabel ;

public TreeNodeChild(String Node){ Parent = new JPanel();

PartRadio = new JRadioButton(); PartLabel = new JLabel(); PartLabel.setText(Node); Parent.add(PartRadio); Parent.add(PartLabel); } }

class DynamicTree extends JPanel { TreeNodeChild rootNode; DefaultTreeModel treeModel; JTree tree;

Toolkit toolkit = Toolkit.getDefaultToolkit(); DynamicTree(){

super(new GridLayout(1,0));

TreeNodeChild rootNode = new TreeNodeChild(\ Node\ treeModel = new DefaultTreeModel(rootNode);

treeModel.addTreeModelListener(new MyTreeModelListener());

tree = new JTree(treeModel); tree.setEditable(true);

tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION); tree.setShowsRootHandles(true);

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