【Java】【事件驱动程序设计——贷款计算器】

深藏阁楼爱情的钟 2022-02-17 13:36 301阅读 0赞

### 运行结果： ###

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0RYSDkyNA_size_16_color_FFFFFF_t_70][]

import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;
    import javax.swing.border.TitledBorder;
    // 贷款类
    class Loan {
    	private double interest;
    	private int year;
    	private double loanAmount;
    	private double monthlyPayment;
    	private double totalPayment;
    	public Loan(double interest, int year, double loanAmount) {
    		this.interest = interest;
    		this.year = year;
    		this.loanAmount = loanAmount;
    		monthlyPayment = loanAmount * interest / 12;
    		totalPayment = loanAmount * interest * year;
    	}
    	public double getMonthlyPayment() {
    		return monthlyPayment;
    	}
    	public double getTotalPayment() {
    		return totalPayment;
    	}
    }
    //
    public class LoanCalculator extends JFrame {
    	private JTextField jtfAnnualIntestRate = new JTextField();
    	private JTextField jtfNumberOfYears = new JTextField();
    	private JTextField jtfLoanAmount = new JTextField();
    	private JTextField jtfMonthlyPayment = new JTextField();
    	private JTextField jtfTotalPayment = new JTextField();
    	private JButton jbtComputeLoan = new JButton("计算支付额");
    	
    	public LoanCalculator() {
    		// 创建一个5行2列的面板p1
    		JPanel p1 = new JPanel(new GridLayout(5, 2));
    		// 将标签和文本域添加到p1中
    		p1.add(new JLabel("年利率"));
    		p1.add(jtfAnnualIntestRate);
    		p1.add(new JLabel("年份"));
    		p1.add(jtfNumberOfYears);
    		p1.add(new JLabel("贷款总额"));
    		p1.add(jtfLoanAmount);
    		p1.add(new JLabel("月支付额"));
    		p1.add(jtfMonthlyPayment);
    		p1.add(new JLabel("总支付额"));
    		p1.add(jtfTotalPayment);
    		p1.setBorder(new TitledBorder("输入年利率，年数及贷款额"));
    		// 创建一个面板p2
    		JPanel p2 = new JPanel(new FlowLayout(FlowLayout.RIGHT));
    		// 将按钮添加到p2中
    		p2.add(jbtComputeLoan);
    		// 将p1放在框架的中央
    		add(p1, BorderLayout.CENTER);
    		// 将p2放在框架的南边
    		add(p2, BorderLayout.SOUTH);
    		// 创建并注册用以处理点击按钮动作事件的监听器
    		jbtComputeLoan.addActionListener(new ButtonListener());
    	}
    	
    	private class ButtonListener implements ActionListener {
    		public void actionPerformed(ActionEvent e) {
    			// 从文本域获取
    			double interest = Double.parseDouble(jtfAnnualIntestRate.getText());
    			int year = Integer.parseInt(jtfNumberOfYears.getText());
    			double loanAmount = Double.parseDouble(jtfLoanAmount.getText());
    			Loan loan = new Loan(interest, year, loanAmount);
    			// 输出计算结果到文本域
    			jtfMonthlyPayment.setText(String.format("%.2f", loan.getMonthlyPayment()));
    			jtfTotalPayment.setText(String.format("%.2f", loan.getTotalPayment()));
    		}
    	}
    	
    	public static void main(String args[]) {
    		LoanCalculator frame = new LoanCalculator();
    		frame.pack();
    		frame.setTitle("贷款计算器");
    		frame.setLocationRelativeTo(null);
    		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    		frame.setSize(500, 300);
    		frame.setVisible(true);
    	}
    }

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0RYSDkyNA_size_16_color_FFFFFF_t_70]: /images/20220217/b2dd4659176d4e4ca4a5c3e973d4c653.png