【课后练习分享】Java用户注册界面设计和求三角形面积的图形界面程序

java编程题（每日一练）：

问题一的答案代码如下：

问题一的运行截图如下：

问题二的答案代码如下：

问题二的运行截图如下：

java编程题（每日一练）：

1.设计一个用户注册的界面，包括用户名、密码输入框，性别单选按钮，表示爱好的篮球、足球、乒乓球复选框，表示学历的下拉列表框，“注册”按钮和“取消”按钮。

2.设计一个求三角形面积的图形界面程序，要求通过3个输入框输入3个边长，当单击“计算”按钮时，能够计算以输入的3个边长所形成的三角形的面积。要求能够判断输入的3个边长是否是数字，三个边长是否能够构成合法的三角形

问题一的答案代码如下：

Java 用户注册界面设计

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;public class Main {public static void main(String[] args) {JFrame frame = new JFrame("User Registration");frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);frame.setSize(400, 300);frame.setLayout(new GridLayout(6, 2));JLabel nameLabel = new JLabel("Username:");JTextField nameField = new JTextField();JLabel passwordLabel = new JLabel("Password:");JPasswordField passwordField = new JPasswordField();JLabel genderLabel = new JLabel("Gender:");JRadioButton maleButton = new JRadioButton("Male");JRadioButton femaleButton = new JRadioButton("Female");ButtonGroup genderGroup = new ButtonGroup();genderGroup.add(maleButton);genderGroup.add(femaleButton);JPanel genderPanel = new JPanel();genderPanel.add(maleButton);genderPanel.add(femaleButton);JLabel hobbyLabel = new JLabel("Hobbies:");JCheckBox basketballBox = new JCheckBox("Basketball");JCheckBox footballBox = new JCheckBox("Football");JCheckBox pingpongBox = new JCheckBox("Ping Pong");JPanel hobbyPanel = new JPanel();hobbyPanel.add(basketballBox);hobbyPanel.add(footballBox);hobbyPanel.add(pingpongBox);JLabel educationLabel = new JLabel("Education:");String[] educationLevels = {"High School", "Associate", "Bachelor", "Master", "Doctor"};JComboBox<String> educationComboBox = new JComboBox<>(educationLevels);JButton registerButton = new JButton("Register");JButton cancelButton = new JButton("Cancel");frame.add(nameLabel);frame.add(nameField);frame.add(passwordLabel);frame.add(passwordField);frame.add(genderLabel);frame.add(genderPanel);frame.add(hobbyLabel);frame.add(hobbyPanel);frame.add(educationLabel);frame.add(educationComboBox);frame.add(registerButton);frame.add(cancelButton);registerButton.addActionListener(new ActionListener() {@Overridepublic void actionPerformed(ActionEvent e) {String username = nameField.getText();String password = new String(passwordField.getPassword());String gender = maleButton.isSelected() ? "Male" : "Female";String hobbies = "";if (basketballBox.isSelected()) hobbies += "Basketball ";if (footballBox.isSelected()) hobbies += "Football ";if (pingpongBox.isSelected()) hobbies += "Ping Pong ";String education = (String) educationComboBox.getSelectedItem();JOptionPane.showMessageDialog(frame, "Username: " + username + "\nPassword: " + password + "\nGender: " + gender + "\nHobbies: " + hobbies + "\nEducation: " + education);}});cancelButton.addActionListener(new ActionListener() {@Overridepublic void actionPerformed(ActionEvent e) {nameField.setText("");passwordField.setText("");genderGroup.clearSelection();basketballBox.setSelected(false);footballBox.setSelected(false);pingpongBox.setSelected(false);educationComboBox.setSelectedIndex(0);}});frame.setVisible(true);}
}

问题一的运行截图如下：

问题二的答案代码如下：

求三角形面积的图形界面程序

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;public class TriangleAreaCalculator {public static void main(String[] args) {JFrame frame = new JFrame("Triangle Area Calculator");frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);frame.setSize(400, 200);frame.setLayout(new GridLayout(5, 2));JLabel sideALabel = new JLabel("Side A:");JTextField sideAField = new JTextField();JLabel sideBLabel = new JLabel("Side B:");JTextField sideBField = new JTextField();JLabel sideCLabel = new JLabel("Side C:");JTextField sideCField = new JTextField();JButton calculateButton = new JButton("Calculate");JLabel resultLabel = new JLabel("Area:");frame.add(sideALabel);frame.add(sideAField);frame.add(sideBLabel);frame.add(sideBField);frame.add(sideCLabel);frame.add(sideCField);frame.add(calculateButton);frame.add(resultLabel);calculateButton.addActionListener(new ActionListener() {@Overridepublic void actionPerformed(ActionEvent e) {try {double a = Double.parseDouble(sideAField.getText());double b = Double.parseDouble(sideBField.getText());double c = Double.parseDouble(sideCField.getText());if (isValidTriangle(a, b, c)) {double s = (a + b + c) / 2;double area = Math.sqrt(s * (s - a) * (s - b) * (s - c));resultLabel.setText("Area: " + area);} else {resultLabel.setText("Invalid Triangle");}} catch (NumberFormatException ex) {resultLabel.setText("Please enter valid numbers");}}});frame.setVisible(true);}public static boolean isValidTriangle(double a, double b, double c) {return a + b > c && a + c > b && b + c > a;}
}