Question

我正在尝试在Java GUI类中创建一个具有以下属性的计算器：

发生操作的文本字段必须由两行组成第1行打印我们的操作第2行打印操作的重新开始
必须按照下图所示的方式组织计算器的按钮：

使用GridLayout和BorderLayout布局管理器我无法获得所需的结果怎么解决这个问题？

我写的代码在

import java.awt.GridLayout;
import java.awt.BorderLayout;

import javax.swing.*;

import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class calculator {
    public static JTextField field;
    public static String pStr="";
    // Create an array containing the buttons texts
    public static final String[][] BUTTON_TEXTS = {
            {" ", " ", "d", " c"},
            {"7", "8", "9", "+"},
            {"4", "5", "6", "-"},
            {"1", "2", "3", "*"},
            {"0", ".", "/", "="}
    };
    // Create the button hnadler 
    private static class ButtonHandler implements ActionListener{
        private static int clicksNumber = 0;
        private String c;

         public void numberButtonsAction(JButton a) {
                this.c = a.getText();
            }
        public void actionPerformed(ActionEvent e){

            clicksNumber ++ ;
            pStr +=((JButton) e.getSource()).getText();
            System.out.println(pStr);
            field.setText(pStr);
        }
    }
    //Create Font used in caluclator
    public static final Font BTN_FONT = new Font(Font.SANS_SERIF, Font.ITALIC, 15);
    public static void main(String[] args){

        // create the field in which the operations are printed
        JTextField text = new JTextField();
        text.setSize(20, 500);
        field = text;
        text.setFont(BTN_FONT); // Set the field font
        JLabel myLabel = new JLabel("Se7002");

        // Create the grid that will contain the buttons
        JPanel btnPanel = new JPanel(new GridLayout(BUTTON_TEXTS.length,
                BUTTON_TEXTS[0].length));

        // Create and Fill grid with buttons
        for(int i=0  ;i<BUTTON_TEXTS.length ; i++){
            for(int j=0 ; j< BUTTON_TEXTS[0].length ; j++){
                JButton btn = new JButton(BUTTON_TEXTS[i][j]);
                btn.setFont(BTN_FONT);
                btn.setSize(60,90);
                btnPanel.add(btn);
                ButtonHandler listener = new ButtonHandler();
                btn.addActionListener(listener);
            }
        }

        //Create the content of the calculator 
        JPanel content =  new JPanel(new BorderLayout());
        content.add(text,BorderLayout.PAGE_START);
        content.add(btnPanel,BorderLayout.CENTER);
        content.add(myLabel,BorderLayout.SOUTH);



        JFrame CalcTest = new JFrame("Calculator");
        CalcTest.setContentPane(content);
        CalcTest.setSize(300,350);
        CalcTest.setLocation(100, 100);
        CalcTest.setVisible(true);
    }

}

Answer 1

这是我提出的计算器GUI：

我对您的代码进行了一些更改。

我删除了几乎所有的静态方法和变量。
我通过在main方法中调用SwingUtilities invokeLater方法在Event Dispatch thread上启动了Java Swing GUI。
我创建了一个Button和Buttons（Java对象）类，因此我可以在一个地方定义计算器按钮。
我使用GridBagLayout来定位计算器按钮。我使用FlowLayout来定位JTextArea。我使用BorderLayout将JTextArea JPanel和计算器按钮JPanel放在JFrame中。我删除了所有绝对定位和间距。
我对代码进行了格式化和组织，以便更容易阅读和修改。
我将JTextArea和计算器按钮的生成分为两种不同的方法。
我没有对动作监听器做任何事情。

这是代码。

package com.ggl.testing;

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Container;
import java.awt.Font;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;

public class Calculator implements Runnable {

    private static final Font BTN_FONT = new Font(Font.SANS_SERIF, Font.ITALIC,
            15);

    private Buttons buttons;

    private JTextArea textArea;

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Calculator());
    }

    public Calculator() {
        buttons = new Buttons();
    }

    @Override
    public void run() {
        JFrame calcTest = new JFrame("Calculator");
        calcTest.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        calcTest.add(createTextPanel(), BorderLayout.NORTH);
        calcTest.add(createButtonPanel(), BorderLayout.SOUTH);

        calcTest.pack();
        calcTest.setLocationByPlatform(true);
        calcTest.setVisible(true);
    }

    private JPanel createTextPanel() {
        JPanel panel = new JPanel();

        // Create the field in which the operations are printed
        textArea = new JTextArea(2, 15);
        textArea.setEditable(false);
        textArea.setFont(BTN_FONT); // Set the field font

        panel.add(textArea);

        return panel;
    }

    private JPanel createButtonPanel() {
        JPanel panel = new JPanel();
        panel.setLayout(new GridBagLayout());

        ButtonHandler buttonHandler = new ButtonHandler();

        for (Button button : buttons.getButtons()) {
            JButton jButton = new JButton(button.getLabel());
            jButton.addActionListener(buttonHandler);
            jButton.setFont(BTN_FONT);
            addComponent(panel, jButton, button.getGridx(), button.getGridy(),
                    button.getGridwidth(), button.getGridheight(),
                    button.getInsets(), GridBagConstraints.LINE_START,
                    GridBagConstraints.BOTH);
        }

        return panel;
    }

    private void addComponent(Container container, Component component,
            int gridx, int gridy, int gridwidth, int gridheight, Insets insets,
            int anchor, int fill) {
        GridBagConstraints gbc = new GridBagConstraints(gridx, gridy,
                gridwidth, gridheight, 1.0D, 1.0D, anchor, fill, insets, 0, 0);
        container.add(component, gbc);
    }

    private class Buttons {
        private List<Button> buttons;

        public Buttons() {
            Insets leftTopInsets = new Insets(10, 10, 4, 4);
            Insets topInsets = new Insets(10, 0, 4, 4);
            Insets rightTopInsets = new Insets(10, 0, 4, 10);
            Insets leftInsets = new Insets(0, 10, 4, 4);
            Insets normalInsets = new Insets(0, 0, 4, 4);
            Insets rightInsets = new Insets(0, 0, 4, 10);
            Insets leftBottomInsets = new Insets(0, 10, 10, 4);
            Insets bottomInsets = new Insets(0, 0, 10, 4);
            Insets rightBottomInsets = new Insets(0, 0, 10, 10);

            this.buttons = new ArrayList<>(18);

            this.buttons.add(new Button("7", 0, 0, 1, 1, leftTopInsets));
            this.buttons.add(new Button("8", 1, 0, 1, 1, topInsets));
            this.buttons.add(new Button("9", 2, 0, 1, 1, topInsets));
            this.buttons.add(new Button("/", 3, 0, 1, 1, topInsets));
            this.buttons.add(new Button("C", 4, 0, 1, 1, rightTopInsets));

            this.buttons.add(new Button("4", 0, 1, 1, 1, leftInsets));
            this.buttons.add(new Button("5", 1, 1, 1, 1, normalInsets));
            this.buttons.add(new Button("6", 2, 1, 1, 1, normalInsets));
            this.buttons.add(new Button("*", 3, 1, 1, 1, normalInsets));
            this.buttons.add(new Button("<-", 4, 1, 1, 1, rightInsets));

            this.buttons.add(new Button("1", 0, 2, 1, 1, leftInsets));
            this.buttons.add(new Button("2", 1, 2, 1, 1, normalInsets));
            this.buttons.add(new Button("3", 2, 2, 1, 1, normalInsets));
            this.buttons.add(new Button("-", 3, 2, 1, 1, normalInsets));
            this.buttons.add(new Button("=", 4, 2, 1, 2, rightBottomInsets));

            this.buttons.add(new Button("0", 0, 3, 2, 1, leftBottomInsets));
            this.buttons.add(new Button(",", 2, 3, 1, 1, bottomInsets));
            this.buttons.add(new Button("+", 3, 3, 1, 1, bottomInsets));
        }

        public List<Button> getButtons() {
            return buttons;
        }

    }

    private class Button {
        private final String label;

        private final int gridx;
        private final int gridy;
        private final int gridwidth;
        private final int gridheight;

        private final Insets insets;

        public Button(String label, int gridx, int gridy, int gridwidth,
                int gridheight, Insets insets) {
            this.label = label;
            this.gridx = gridx;
            this.gridy = gridy;
            this.gridwidth = gridwidth;
            this.gridheight = gridheight;
            this.insets = insets;
        }

        public String getLabel() {
            return label;
        }

        public int getGridx() {
            return gridx;
        }

        public int getGridy() {
            return gridy;
        }

        public int getGridwidth() {
            return gridwidth;
        }

        public int getGridheight() {
            return gridheight;
        }

        public Insets getInsets() {
            return insets;
        }

    }

    // Create the button handler
    private class ButtonHandler implements ActionListener {
        private int clicksNumber = 0;
        private String c;

        public void numberButtonsAction(JButton a) {
            this.c = a.getText();
        }

        public void actionPerformed(ActionEvent e) {
            clicksNumber++;
            String pStr = ((JButton) e.getSource()).getText();
            System.out.println(pStr);
        }
    }

}

Java中有两行文本字段的计算器

1 个答案: