Java程序设计项目式教程（含实训任务单）习题答案 单元10 课后作业及参考答案

课后作业一、填空题1.Java.awt包、Java.swing包2.FlowLayout、BorderLayout、GridLayout、CardLayout3.JFrame（框架）、JPanel（面板）4.ActionEvent、ActionListener、actionPerformed

5.BorderLayout，FlowLayout二、设计题1.编写一个应用程序，接受用户输入的账号和密码，给出三次机会。参考代码：packagechapter10_1;importjava.awt.*;importjava.awt.event.*;importjavax.swing.*;importjavax.swing.border.*;publicclassLoginJFrameextendsJFrameimplementsActionListener{ JTextFieldunameField; JPasswordFieldupwdField; intcount=3; publicLoginJFrame(Stringtitle){ super(title); //创建JLabel对象， JLabelunameJLabel=newJLabel("用户名:"); JLabelupwdJLabel=newJLabel("密码："); //创建JTextField对象，JPassword对象 unameField=newJTextField(14); upwdField=newJPasswordField(14); //创建JButton按钮 JButtonconfirmButton=newJButton("登录"); JButtoncancelButton=newJButton("重置"); confirmButton.addActionListener(this); //创建用户名面板 JPanelunamePanel=newJPanel(); unamePanel.setBorder(newEmptyBorder(20,0,0,0)); unamePanel.add(unameJLabel); unamePanel.add(unameField); //创建密码面板 JPanelupwdPanel=newJPanel(); upwdPanel.setBorder(newEmptyBorder(10,0,0,0)); upwdPanel.add(upwdJLabel); upwdPanel.add(upwdField); //创建按钮面板 JPanelbuttonPanel=newJPanel(); buttonPanel.setBorder(newEmptyBorder(10,0,0,0)); buttonPanel.add(confirmButton); buttonPanel.add(cancelButton); //将控件加入主界面 this.add(unamePanel); this.add(upwdPanel); this.add(buttonPanel); //设置窗体相关特性 setSize(450,300); setLayout(newGridLayout(4,1)); setVisible(true); setDefaultCloseOperation(EXIT_ON_CLOSE); } publicvoidactionPerformed(ActionEvente){Stringusername=unameField.getText();Stringpassword=newString(upwdField.getPassword());if(count>0){ if(username.equals("admin")&&password.equals("123456")){ JOptionPane.showMessageDialog(null,"登录成功"); }else{ count--; JOptionPane.showMessageDialog(null,"用户名或密码错误，还有"+count+"次机会"); }}} publicstaticvoidmain(String[]args){ newLoginJFrame("登录"); }}2.设计一个界面有一个文本框和三个按钮，当按下每个按钮时，使不同的文字显示在文本框中。参考代码：packagechapter10_2;importjavax.swing.*;importjava.awt.*;importjava.awt.event.*;publicclassJButtonDemoextendsJFrameimplementsActionListener{privateJTextFieldtextField;privateJButtonbutton1,button2,button3;publicJButtonDemo(){setTitle("ButtonDemo");setSize(300,200);setLocationRelativeTo(null);setDefaultCloseOperation(EXIT_ON_CLOSE);initComponents();}privatevoidinitComponents(){textField=newJTextField(20);button1=newJButton("Button1");button2=newJButton("Button2");button3=newJButton("Button3");button1.addActionListener(this);button2.addActionListener(this);button3.addActionListener(this);JPanelpanel=newJPanel(newBorderLayout());panel.add(textField,BorderLayout.NORTH);panel.add(button1,BorderLayout.WEST);panel.add(button2,BorderLayout.CENTER);panel.add(button3,BorderLayout.EAST);getContentPane().add(panel);}publicvoidactionPerformed(ActionEvente){if(e.getSource()==button1){textField.setText("Button1clicked");}elseif(e.getSource()==button2){textField.setText("Button2clicked");}elseif(e.getSource()==button3){textField.setText("Button3clicked");}}publicstaticvoidmain(String[]args){JButtonDemojFrame=newJButtonDemo();jFrame.setVisible(true);}}3.完成图10-20所示图形.。用菜单或按钮完成算术运算，当除数为零时，给出提示信息。参考代码：packagechapter10_3;importjava.awt.*;importjava.awt.event.*;importjavax.swing.*;publicclassMenuBarCalcextendsJFrameimplementsActionListener{ JButtonbtnAdd,btnSub,btnMul,btnDiv; JTextFieldtxtNum1,txtNum2,txtResult; publicMenuBarCalc(){ JMenuBarjmenuBar=newJMenuBar(); // JMenufileMenu=newJMenu("退出"); JMenueditMenu=newJMenu("操作"); jmenuBar.add(editMenu);//添加到菜单栏中 jmenuBar.add(fileMenu); // JMenuItemaddMenuItem=newJMenuItem("加"); JMenuItemsubMenuItem=newJMenuItem("减"); JMenuItemmulMenuItem=newJMenuItem("乘"); JMenuItemdivMenuItem=newJMenuItem("除"); editMenu.add(addMenuItem); editMenu.add(subMenuItem); editMenu.add(addMenuItem); editMenu.add(mulMenuItem); editMenu.add(divMenuItem); addMenuItem.addActionListener(this); subMenuItem.addActionListener(this); mulMenuItem.addActionListener(this); divMenuItem.addActionListener(this); // // this.setJMenuBar(jmenuBar);//将菜单条设置为当前窗口的菜单条 // btnAdd=newJButton("加"); btnSub=newJButton("减"); btnMul=newJButton("乘"); btnDiv=newJButton("除"); btnAdd.addActionListener(this); btnSub.addActionListener(this); btnMul.addActionListener(this); btnDiv.addActionListener(this); // txtNum1=newJTextField(8); txtNum2=newJTextField(8); txtResult=newJTextField(8); // txtResult.setEditable(false); // JPaneljPanel1=newJPanel(); jPanel1.add(newJLabel("number1:")); jPanel1.add(txtNum1); jPanel1.add(newJLabel("number2:")); jPanel1.add(txtNum2); jPanel1.add(newJLabel("result:")); jPanel1.add(txtResult); JPaneljPanel2=newJPanel(); jPanel2.add(btnAdd); jPanel2.add(btnSub); jPanel2.add(btnMul); jPanel2.add(btnDiv); this.setLayout(newGridLayout(2,1)); this.add(jPanel1); this.add(jPanel2); } @Override publicvoidactionPerformed(ActionEvente){ Stringnum1str=txtNum1.getText(); Stringnum2str=txtNum2.getText(); intnum1=0,num2=0; try{ num1=Integer.parseInt(num1str); num2=Integer.parseInt(num2str); }catch(Exceptione1){ } switch(e.getActionCommand()){ case"加": txtResult.setText(num1+num2+""); break; case"减": txtResult.setText(num1-num2+""); break; case"乘": txtResult.setText(num1*num2+""); break; case"除": if(num2!=0){ txtResult.setText(num1/num2+""); }else{ JOptionPane.showMessageDialog(null,"除数不能为0"); } break; } } publicstaticvoidmain(String[]args){ MenuBarCalcframe=newMenuBarCalc(); frame.setSize(500,170); frame.setTitle("计算器"); // frame.setVisible(true); } }4.完成图10-21所示图形界面的设计，当单击“验证”按钮，弹出一个确认对话框，“重置”按钮则清除已输入的数据。参考代码：packagechapter10_4;importjava.awt.FlowLayout;importjava.awt.GridLayout;importjava.awt.event.ActionEvent;importjava.awt.event.ActionListener;importjavax.swing.ButtonGroup;importjavax.swing.JButton;importjavax.swing.JCheckBox;importjavax.swing.JComboBox;importjavax.swing.JFrame;importjavax.swing.JLabel;importjavax.swing.JOptionPane;importjavax.swing.JPanel;importjavax.swing.JRadioButton;importjavax.swing.JTextArea;importjavax.swing.JTextField;publicclassStudentJFrameextendsJFrameimplementsActionListener{ privateJTextFieldsname; privateJRadioButtonsgenderMale,sgenderFemale; privateButtonGroupbggender; privateJCheckBoxjCheckBox1,jCheckBox2,jCheckBox3; privateJTextAreasadress; privateJComboBoxjcb; privateJButtonbtnCheck,btnReset; publicStudentJFrame(){ setTitle("学生详细信息"); setBounds(100,100,460,460); // JPaneljPanel1=newJPanel(newFlowLayout(FlowLayout.LEFT)); sname=newJTextField(""); sname.setColumns(12); jPanel1.add(newJLabel("姓名：")); jPanel1.add(sname); jPanel1.add(newJLabel("学历：")); jcb=newJComboBox(); jcb.addItem("专科"); jcb.addItem("本科"); jcb.addItem("硕士研究生"); jcb.addItem("本科研究生"); jPanel1.add(jcb); JPaneljPanel2=newJPanel(newFlowLayout(FlowLayout.LEFT)); jPanel2.add(newJLabel("地址：")); sadress=newJTextArea(4,12); jPanel2.add(sadress); jPanel2.add(newJLabel("兴趣：")); JPanelhabitPanel=newJPanel(); habitPanel.setLayout(newGridLayout(3,1)); jCheckBox1=newJCheckBox("阅读"); jCheckBox2=newJCheckBox("唱歌"); jCheckBox3=newJCheckBox("跳舞"); habitPanel.add(jCheckBox1); habitPanel.add(jCheckBox2); habitPanel.add(jCheckBox3); jPanel2.add(habitPanel); // JPaneljPanel3=newJPanel(newFlowLayout(FlowLayout.LEFT)); jPanel3.add(newJLabel("性别：")); sgenderMale=newJRadioButton("男"); sgenderFemale=newJRadioButton("女"); sgenderMale.setSelected(true); bggender=newButtonGroup(); bggender.add(sgenderMale); bggender.add(sgenderFemale); jPanel3.add(sgenderMale); jPanel3.add(sgenderFemale); JPaneljPanel4=newJPanel(newFlowLayout(FlowLayout.LEFT,80,0)); btnC