JRadioButton 未正确显示

Question

我想创建一个简单的食品订购系统，现在我正在创建订单表单的界面。我使用 GridBagLayout 来创建表单布局，我的问题是当我想在同一行中分配 3 个单选按钮时，它只显示 1 个按钮......我希望有人可以帮助我......这是我的java代码：import java.awt.*;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.ItemEvent;import java.awt.event.ItemListener;import javax.swing.*;/** * * @author user */public class ChickenChopOrderingSystem{    JFrame frame;    JPanel mainPanel, p1, p2, p3, p4;    JLabel lblTitle, lblName, lblPhoneNum, lblFlavour, lblChickenPart;    JTextField txtName, txtPhoneNum;    String flavour[] = {"Black Pepper Sauce", "Hainanese", "Grilled", "Lemon"};    JComboBox box;    ButtonGroup bg = new ButtonGroup();    JRadioButton btnWhole, btnHalf, btnQuarter;    JButton btnDone, btnExit;    public ChickenChopOrderingSystem()    {        frame = new JFrame("Chicken Chop Ordering System");        mainPanel = new JPanel();        mainPanel.setPreferredSize(new Dimension(700,700));        mainPanel.setBackground(Color.yellow);        lblName = new JLabel("Customer's Name: ");            txtName = new JTextField(20);        lblPhoneNum = new JLabel("Phone Number: ");            txtPhoneNum = new JTextField(11);        lblChickenPart = new JLabel("Select Part of Chicken: ");            btnWhole = new JRadioButton("Whole");                btnWhole.addItemListener(new OperationListener());            btnHalf = new JRadioButton("Half");                btnHalf.addItemListener(new OperationListener());            btnQuarter = new JRadioButton("Quarter");                btnQuarter.addItemListener(new OperationListener());            bg.add(btnWhole);            bg.add(btnHalf);    }单击此处查看输出

Answer 1

对于这样的事情：

使用此代码：

import java.awt.*;

import javax.swing.*;

public class ChickenChopOrderingSystem {

    JFrame frame;

    JPanel mainPanel, p1, p2, p3, p4;

    JLabel lblTitle, lblName, lblPhoneNum, lblFlavour, lblChickenPart;

    JTextField txtName, txtPhoneNum;

    String flavour[] = {"Black Pepper Sauce", "Hainanese", "Grilled", "Lemon"};

    JComboBox box;

    ButtonGroup bg = new ButtonGroup();

    JRadioButton btnWhole, btnHalf, btnQuarter;

    JButton btnDone, btnExit;

    public ChickenChopOrderingSystem() {

        frame = new JFrame("Chicken Chop Ordering System");

        mainPanel = new JPanel();

        // GUESSWORK! 

        //mainPanel.setPreferredSize(new Dimension(700,700));

        mainPanel.setBackground(Color.yellow);

        lblName = new JLabel("Customer's Name: ");

        txtName = new JTextField(20);

        lblPhoneNum = new JLabel("Phone Number: ");

        txtPhoneNum = new JTextField(11);

        lblChickenPart = new JLabel("Select Part of Chicken: ");

        btnWhole = new JRadioButton("Whole");

        btnHalf = new JRadioButton("Half");

        btnQuarter = new JRadioButton("Quarter");

        bg.add(btnWhole);

        bg.add(btnHalf);

        bg.add(btnQuarter);

        lblFlavour = new JLabel("Select a flavour: ");

        box = new JComboBox(flavour);

        btnDone = new JButton("Done");

        btnExit = new JButton("Exit");

        //GridBaglayout

        mainPanel.setLayout(new GridBagLayout());

        GridBagConstraints gbc = new GridBagConstraints();

        int s = 20;

        gbc.insets = new Insets(s,s,s,s);

        //Label

        gbc.fill = GridBagConstraints.HORIZONTAL;

        gbc.gridx = 0;

        gbc.gridy = 0;

        gbc.weightx = 0.5;

        gbc.weighty = 0.5;

        mainPanel.add(lblName, gbc);

        gbc.fill = GridBagConstraints.HORIZONTAL;

        gbc.gridx = 0;

        gbc.gridy = 1;

        gbc.weightx = 0.5;

        mainPanel.add(lblPhoneNum, gbc);

        gbc.fill = GridBagConstraints.HORIZONTAL;

        gbc.gridx = 0;

        gbc.gridy = 2;

        gbc.weightx = 0.5;

        mainPanel.add(lblChickenPart, gbc);

        gbc.fill = GridBagConstraints.HORIZONTAL;

        gbc.gridx = 0;

        gbc.gridy = 3;

        gbc.weightx = 0.5;

        mainPanel.add(lblFlavour, gbc);

        //TextField

        gbc.fill = GridBagConstraints.HORIZONTAL;

        gbc.gridx = 1;

        gbc.gridy = 0;

        gbc.gridwidth = 3;

        mainPanel.add(txtName, gbc);

        gbc.fill = GridBagConstraints.HORIZONTAL;

        gbc.gridx = 1;

        gbc.gridy = 1;

        gbc.gridwidth = 3;

        mainPanel.add(txtPhoneNum, gbc);

        gbc.fill = GridBagConstraints.HORIZONTAL;

        gbc.gridx = 1;

        gbc.gridy = 2;

        gbc.gridwidth = 1;

        gbc.weightx = 1d/6d;

        mainPanel.add(btnWhole, gbc);

        gbc.gridx = 2;

        gbc.gridy = 2;

        mainPanel.add(btnHalf, gbc);

        gbc.gridx = 3;

        gbc.gridy = 2;

        mainPanel.add(btnQuarter, gbc);

        gbc.fill = GridBagConstraints.HORIZONTAL;

        gbc.gridx = 1;

        gbc.gridy = 3;

        gbc.gridwidth = 3;

        mainPanel.add(box, gbc);

        //frame setting

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        frame.setLayout(new GridBagLayout());

        frame.add(mainPanel, new GridBagConstraints());

        // GUESSWORK! 

        //frame.setSize(new Dimension(1000, 1000));

        frame.pack();

        frame.setVisible(true);

    }

    public static void main(String[] args) {

        ChickenChopOrderingSystem run = new ChickenChopOrderingSystem();

    }

}

原来的代码存在很多问题。（拖网记忆..）

• 最后一个元素的约束没有设置回网格宽度 3，这让布局管理器感到困惑。

• 他们ItemListener在移除组件时做了一些奇怪的事情，不要这样做。

• 面板的首选尺寸和框架的尺寸都是猜测。用于pack()计算正确的尺寸。Inserts（向空白的初始约束添加标准。）