Java抵押计算器GUI问题

Question

我对编程有点陌生，至少是用Java编程，我现在正在上课，我只是需要有人给我指个方向。

我有一个问题，让所有的jpanel显示在应用程序屏幕上的特定位置。剩下的计算应该是小菜一碟。

下面是我到目前为止写的代码:

import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.*;
import java.text.NumberFormat;
import java.awt.GridLayout;
public class MortgageCalculatorGUI7 extends JFrame {
            JPanel panel1 = new JPanel(new FlowLayout());
            JRadioButton b7Yr = new JRadioButton("7 Years",false);
            JRadioButton b15Yr = new JRadioButton("15 Years",false);
            JRadioButton b30Yr = new JRadioButton("30 Years",false);
            JRadioButton b535Int = new JRadioButton("5.35% Interest",false);
            JRadioButton b55Int = new JRadioButton("5.5% Interest",false);
            JRadioButton b575Int = new JRadioButton("5.75% Interest",false);
            JPanel panel2 = new JPanel(new FlowLayout());
            JLabel mortgageLabel = new JLabel("Mortgage Amount $", JLabel.LEFT);
            JTextField mortgageText = new JTextField(10);
            JLabel termLabel = new JLabel("Mortgage Term (Years)", JLabel.LEFT);
            JTextField termText = new JTextField(3);
            JLabel intRateLabel = new JLabel("Interest Rate (%)", JLabel.LEFT);
            JTextField intRateText = new JTextField(5);
            JLabel mPaymentLabel = new JLabel("Monthly Payment $", JLabel.LEFT);
            JTextField mPaymentText = new JTextField(10);
            JPanel panel3 = new JPanel(new FlowLayout());
            JButton calculateButton = new JButton("CALCULATE");
            JButton clearButton = new JButton("CLEAR");
            JButton exitButton = new JButton("EXIT");

            JPanel panel4 = new JPanel(new FlowLayout());
            JLabel paymentLabel = new JLabel ("Payment #");
            JLabel balLabel = new JLabel (" Balance");
            JLabel ytdPrincLabel = new JLabel (" Principal");
            JLabel ytdIntLabel = new JLabel (" Interest");
            JPanel panel5 = new JPanel(new FlowLayout());
            JTextArea textArea = new JTextArea(10, 31);
        public MortgageCalculatorGUI7() {
            this.setLayout (new BorderLayout());
            panel1.setLayout (new FlowLayout());
            panel2.setLayout (new FlowLayout());
            panel3.setLayout (new FlowLayout());
            panel4.setLayout (new FlowLayout());
            panel5.setLayout (new FlowLayout());
            panel1.add (b7Yr);
            panel1.add (b15Yr);
            panel1.add (b30Yr);
            panel1.add (b535Int);
            panel1.add (b55Int);
            panel1.add (b575Int);
            panel2.add (mortgageLabel);
            panel2.add (mortgageText);
            panel2.add (termLabel);
            panel2.add (termText);
            panel2.add (intRateLabel);
            panel2.add (intRateText);
            panel2.add (mPaymentLabel);
            panel2.add (mPaymentText);
            panel3.add (calculateButton);
            panel3.add (clearButton);
            panel3.add (exitButton);
            panel4.add (paymentLabel);
            panel4.add (balLabel);
            panel4.add (ytdPrincLabel);
            panel4.add (ytdIntLabel);
            panel5.add (textArea);
            add(panel2, BorderLayout.NORTH);
            add(panel1, BorderLayout.CENTER);
            add(panel4, BorderLayout.AFTER_LINE_ENDS);
            add(panel5, BorderLayout.EAST);
            add(panel3, BorderLayout.SOUTH);
            exitButton.addActionListener(new ActionListener(){
                public void actionPerformed(ActionEvent e)
                {
                    System.exit(0);
                }});    
        }
    public static void main(String[] args) {
        MortgageCalculatorGUI7 frame = new MortgageCalculatorGUI7();
        frame.setBounds (200,200,800,500);
        frame.setTitle ("Mortgage Calculator 1.0.4");
        frame.setDefaultCloseOperation (EXIT_ON_CLOSE);
        frame.setVisible (true);
    }
}

Answer 1

FlowLayout只是众多选择之一。我建议你看看不同的布局管理器，找到一个适合你的需求。

Answer 2

如果您的要求定位组件不是太复杂，我建议您使用空布局来精确地使用坐标定位组件。

这是一个正在运行的例子:

import javax.swing.*;
import javax.swing.border.*;
public class MortgageCalculatorGUI7 extends JFrame {

    JPanel panel1 = new JPanel();
    public MortgageCalculatorGUI7() {
        getContentPane().setLayout(null);
        setSize(400, 400);
        panel1.setLayout(null);
        panel1.setBounds(0, 0 , 400, 400);
        add(panel1);

        JLabel label1 = new JLabel("a label");
        label1.setBounds(15, 15, 150, 30);
        label1.setBorder(new BevelBorder(BevelBorder.RAISED));
        panel1.add(label1);

        JLabel label2 = new JLabel("a label");
        label2.setBounds(100, 100, 150, 30);
        label2.setBorder(new BevelBorder(BevelBorder.RAISED));
        panel1.add(label2);
        JLabel label3 = new JLabel("a label");
        label3.setBounds(200, 200, 150, 30);
        label3.setBorder(new BevelBorder(BevelBorder.RAISED));
        panel1.add(label3);

    }
    public static void main(String[] args) {
        MortgageCalculatorGUI7 mortgageCalculatorGUI7 = new MortgageCalculatorGUI7();
        mortgageCalculatorGUI7.setDefaultCloseOperation(EXIT_ON_CLOSE);
        mortgageCalculatorGUI7.setVisible(true);
    }
}