Question

我正在制作一个项目来制作一个小费计算器，它有两个15％和20％的复选框和一个文本框，允许你输入自己的％，我只是无法弄清楚如何链接复选框和文本框会影响答案。我只是希望有人能指出将这些事情联系在一起所需要的东西。

INCLUDE Irvine32.inc

.data
count = 5
scores DWORD count DUP(0)
prompt BYTE "Please type an integer score: ", 0
.code

GetScores PROTO, dwArray:PTR DWORD, arraySize : DWORD

main PROC
exit
main ENDP

GetScores PROC, dwArray:PTR DWORD, arraySize : DWORD

ret
GetScores ENDP

END main

Answer 1

基本答案是，检查每个JCheckBox以查看它是否已被选中，并根据选择的那个，将它所代表的金额分配给某个变量。这需要您了解有关JCheckBox的问题。

你可以：

使用实例字段并简单地检查每个实例字段以查看它们是否被选中，如果您有大量字段，这将成为一个问题
使用组件putClientProperty到getClientProperty功能来针对每个字段中的键存储对象，个人而言，这有点脏，因为你需要进行对象转换，容易出错
使用某种模型和Action API

此示例使用简单的“模型”和Action API来设置基本功能。

“模型”保持当前选择的百分比。选择其中一个可用选项后，模型会自动更新。当用户按下“计算”按钮时，从“模型”获得尖端百分比并进行计算

import java.awt.Color;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.NumberFormat;
import javax.swing.AbstractAction;
import static javax.swing.Action.NAME;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JSpinner;
import javax.swing.SpinnerNumberModel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.EmptyBorder;
import javax.swing.border.LineBorder;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private JSpinner subTotal;
        private JSpinner custom;
        private JButton btnCalculate;

        private TipModel model;

        private JLabel tipAmountLabel;
        private JLabel billTotalLabel;

        public TestPane() {
            setBorder(new EmptyBorder(10, 10, 10, 10));
            subTotal = new JSpinner(new SpinnerNumberModel());
            subTotal.setValue(0d);
            subTotal.setEditor(new JSpinner.NumberEditor(subTotal, "$#0.0#"));

            model = new TipModel();

            custom = new JSpinner(new SpinnerNumberModel(0, 0, 1, 0.05));
            custom.setEditor(new JSpinner.NumberEditor(custom, "##%"));

            JCheckBox cb15 = new JCheckBox(new TipAction(model, 0.15d));
            JCheckBox cb20 = new JCheckBox(new TipAction(model, 0.20d));
            JCheckBox cbCustom = new JCheckBox(new CustomTipAction(model, custom));

            ButtonGroup bg = new ButtonGroup();
            bg.add(cb15);
            bg.add(cb20);
            bg.add(cbCustom);

            btnCalculate = new JButton("Calculate Tip");
            btnCalculate.setMargin(new Insets(10, 10, 10, 10));

            tipAmountLabel = new JLabel("...");
            billTotalLabel = new JLabel("...");
            billTotalLabel.setHorizontalAlignment(JLabel.CENTER);
            tipAmountLabel.setHorizontalAlignment(JLabel.CENTER);

            setLayout(new GridBagLayout());

            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 0;
            gbc.fill = GridBagConstraints.HORIZONTAL;
            gbc.gridwidth = GridBagConstraints.REMAINDER;
            gbc.insets = new Insets(2, 2, 2, 2);
            add(subTotal, gbc);

            gbc.anchor = GridBagConstraints.WEST;
            gbc.gridy++;
            gbc.fill = GridBagConstraints.NONE;
            add(cb15, gbc);
            gbc.gridy++;
            add(cb20, gbc);
            gbc.gridwidth = 1;
            gbc.gridy++;
            add(cbCustom, gbc);

            gbc.gridx++;
            gbc.fill = GridBagConstraints.HORIZONTAL;
            add(custom, gbc);

            gbc.gridx = 0;
            gbc.gridy++;
            gbc.gridwidth = GridBagConstraints.REMAINDER;
            add(btnCalculate, gbc);

            gbc.anchor = GridBagConstraints.CENTER;
            gbc.gridy++;
            add(tipAmountLabel, gbc);
            gbc.gridy++;
            add(billTotalLabel, gbc);

            btnCalculate.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    double tipPercentage = model.getTipPercentage();

                    if (tipPercentage > 0.0) {

                        double subTotalAmount = (double) subTotal.getValue();
                        double tipAmount = subTotalAmount * tipPercentage;
                        double billTotal = subTotalAmount + tipAmount;

                        tipAmountLabel.setText("Tip amount: " + NumberFormat.getCurrencyInstance().format(tipAmount));
                        billTotalLabel.setText("Bill total: " + NumberFormat.getCurrencyInstance().format(billTotal));

                    } else {
                        JOptionPane.showMessageDialog(TestPane.this, "Please provide a valid tip percentage");
                    }
                }
            });
        }

        public class TipModel {

            private double tipPercentage;

            public double getTipPercentage() {
                return tipPercentage;
            }

            public void setTipPercentage(double tipPercentage) {
                this.tipPercentage = tipPercentage;
            }

        }

        public class TipAction extends AbstractAction {

            private TipModel model;
            private double tipPercentage;

            public TipAction(TipModel model, double tipPercentage) {
                this.model = model;
                this.tipPercentage = tipPercentage;
                putValue(NAME, NumberFormat.getPercentInstance().format(tipPercentage));
            }

            @Override
            public void actionPerformed(ActionEvent e) {
                model.setTipPercentage(tipPercentage);
            }

        }

        public class CustomTipAction extends AbstractAction {

            private TipModel model;
            private JSpinner spinner;

            public CustomTipAction(TipModel model, JSpinner spinner) {
                this.model = model;
                this.spinner = spinner;

                spinner.addChangeListener(new ChangeListener() {
                    @Override
                    public void stateChanged(ChangeEvent e) {
                        model.setTipPercentage((double) spinner.getValue());
                    }
                });
            }

            @Override
            public void actionPerformed(ActionEvent e) {
                model.setTipPercentage((double) spinner.getValue());
            }

        }

    }

}

避免使用null布局，像素完美布局是现代ui设计中的一种幻觉。影响组件个体大小的因素太多，您无法控制。 Swing旨在与布局管理器一起工作，放弃这些将导致问题和问题的终结，您将花费越来越多的时间来纠正

看看：

了解更多详情

使用复选框和文本框进行小费计算器

1 个答案: