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Java 分区计算器接口

java swing

Java 分区计算器接口,java,swing,calculator,Java,Swing,Calculator,在这段代码中，前三个按钮出现在文本区域中，如何使这些按钮从标题下方开始？在添加按钮之前，buttonarea从标题下方开始，但一旦添加按钮，它就会出现在标题上 public Design () { header = new JPanel (); header.setBounds(0, 0, 300, 100); header.setBackground(Color.WHITE); header.setLayout (null); butto

在这段代码中，前三个按钮出现在文本区域中，如何使这些按钮从标题下方开始？在添加按钮之前，buttonarea从标题下方开始，但一旦添加按钮，它就会出现在标题上

   public Design ()
   {

    header = new JPanel ();
    header.setBounds(0, 0, 300, 100);
    header.setBackground(Color.WHITE);
    header.setLayout (null);

    buttonarea = new JPanel ();
    buttonarea.setBounds (0,0, 300, 300);
    buttonarea.setBackground(Color.BLACK);
    buttonarea.setLayout(new GridLayout (6,3));

    add (header);
    add (buttonarea);

    zero = new JButton ("0");
    zero.setBackground(Color.PINK);
    one = new JButton ("1");
    one.setBackground(Color.PINK);
    two = new JButton ("2");
    two.setBackground(Color.PINK);
    three = new JButton ("3");
    three.setBackground(Color.PINK);
    four = new JButton ("4");
    four.setBackground(Color.PINK);
    five = new JButton ("5");
    five.setBackground(Color.PINK);
    six = new JButton ("6");
    six.setBackground(Color.PINK);
    seven = new JButton ("7");
    seven.setBackground(Color.PINK);
    eight = new JButton ("8");
    eight.setBackground(Color.PINK);
    nine = new JButton ("9");
    nine.setBackground(Color.PINK);
    add = new JButton ("+");
    add.setBackground(Color.PINK);
    subtract = new JButton ("-");
    subtract.setBackground(Color.PINK);
    divide = new JButton ("*");
    divide.setBackground(Color.PINK);
    multiply = new JButton ("/");
    multiply.setBackground(Color.PINK);
    square = new JButton ("x^2");
    square.setBackground(Color.PINK);
    equal = new JButton ("=");
    equal.setBackground(Color.PINK);
    c = new JButton ("C");
    c.setBackground(Color.PINK);
    clear = new JButton ("delete");
    clear.setBackground(Color.PINK);
    dot = new JButton (".");
    dot.setBackground(Color.PINK);

    written = new JTextArea ();
    written.setBackground(Color.WHITE);

   header.add (written);

    buttonarea.add (c);
    buttonarea.add (clear);
    buttonarea.add (equal);
    buttonarea.add (zero);
    buttonarea.add (one);
    buttonarea.add (add);
    buttonarea.add (two);   
    buttonarea.add (three);
    buttonarea.add (subtract);
    buttonarea.add (four);
    buttonarea.add (five);
    buttonarea.add (multiply);
    buttonarea.add (six);
    buttonarea.add (seven);
    buttonarea.add (square);
    buttonarea.add (eight); 
    buttonarea.add (nine);    
    buttonarea.add (dot);  
   }
虽然空布局和设置框似乎是让新手喜欢的创建复杂GUI的最简单和最好的方法，但您创建的GUI越多，在使用它们时遇到的困难就越严重。当GUI调整大小时，它们不会调整您的组件的大小，它们是一个需要增强或维护的皇家女巫，当它们放置在滚动窗格中时会完全失败，当在所有平台或屏幕分辨率与原始分辨率不同的情况下查看时，它们看起来非常糟糕

在主GUI中使用BorderLayout，将JTextField BorderLayout.PAGE_放置在开始位置。使用JPanel将JButtons放置在GridLayout中，并将此JPanel放置在主GUI的BorderLayout.CENTER位置

例如，此GUI：

import java.awt.BorderLayout;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;

@SuppressWarnings("serial")
public class SimpleCalc extends JPanel {
    private static final String[][] BTN_TEXTS = {
        {"C", "Del", "X^2", "+"},
        {"7", "8", "9", "-"},
        {"4", "5", "6", "*"},
        {"1", "2", "3", "/"},
        {"0", ".", "", "="}
    };
    private static final int COLS = 12;
    private static final int GAP = 3;
    private static final char[] NUMBER_ARRAY = "0123456789".toCharArray();
    private static final List<Character> NUMBER_LIST = new ArrayList<>();
    private static final float FONT_SIZE = 36f;
    private JTextField display = new JTextField(COLS);

    static {
        for (char c : NUMBER_ARRAY) {
            NUMBER_LIST.add(c);
        }
    }

    public SimpleCalc() {
        display.setFont(display.getFont().deriveFont(FONT_SIZE));
        display.setFocusable(false);

        int rows = BTN_TEXTS.length;
        int cols = BTN_TEXTS[0].length;
        JPanel buttonPanel = new JPanel(new GridLayout(rows, cols, GAP, GAP));
        for (String[] btnTextRow : BTN_TEXTS) {
            for (String btnText : btnTextRow) {
                if (btnText.isEmpty()) {
                    buttonPanel.add(new JLabel());
                } else {
                    Action action = null;
                    if (NUMBER_LIST.contains(btnText.charAt(0))) {
                        action = new NumericAction(btnText);
                    } else if (".".equals(btnText)) {
                        action = new DotAction(btnText);
                    } else {
                        action = new OperationAction(btnText);
                    }
                    JButton button = new JButton(action);
                    button.setFont(button.getFont().deriveFont(Font.BOLD, FONT_SIZE));
                    buttonPanel.add(button);
                }
            }
        }

        setBorder(BorderFactory.createEmptyBorder(GAP, GAP, GAP, GAP));
        setLayout(new BorderLayout(GAP, GAP));
        add(display, BorderLayout.PAGE_START);
        add(buttonPanel, BorderLayout.CENTER);
    }

    private class NumericAction extends AbstractAction {
        public NumericAction(String name) {
            super(name);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            String text = display.getText();
            text += e.getActionCommand();
            display.setText(text);
        }
    }

    private class DotAction extends AbstractAction {
        public DotAction(String name) {
            super(name);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            String text = display.getText();
            if (text.contains(".")) {
                return; // only one dot allowed
            }
            text += e.getActionCommand();
            display.setText(text);
        }
    }

    private class OperationAction extends AbstractAction {
        public OperationAction(String name) {
            super(name);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            // TODO write code for operations buttons
        }
    }

    private static void createAndShowGui() {
        SimpleCalc mainPanel = new SimpleCalc();

        JFrame frame = new JFrame("SimpleCalc");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.getContentPane().add(mainPanel);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGui();
            }
        });
    }
}
可以使用此GUI进行以下操作：

import java.awt.BorderLayout;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;

@SuppressWarnings("serial")
public class SimpleCalc extends JPanel {
    private static final String[][] BTN_TEXTS = {
        {"C", "Del", "X^2", "+"},
        {"7", "8", "9", "-"},
        {"4", "5", "6", "*"},
        {"1", "2", "3", "/"},
        {"0", ".", "", "="}
    };
    private static final int COLS = 12;
    private static final int GAP = 3;
    private static final char[] NUMBER_ARRAY = "0123456789".toCharArray();
    private static final List<Character> NUMBER_LIST = new ArrayList<>();
    private static final float FONT_SIZE = 36f;
    private JTextField display = new JTextField(COLS);

    static {
        for (char c : NUMBER_ARRAY) {
            NUMBER_LIST.add(c);
        }
    }

    public SimpleCalc() {
        display.setFont(display.getFont().deriveFont(FONT_SIZE));
        display.setFocusable(false);

        int rows = BTN_TEXTS.length;
        int cols = BTN_TEXTS[0].length;
        JPanel buttonPanel = new JPanel(new GridLayout(rows, cols, GAP, GAP));
        for (String[] btnTextRow : BTN_TEXTS) {
            for (String btnText : btnTextRow) {
                if (btnText.isEmpty()) {
                    buttonPanel.add(new JLabel());
                } else {
                    Action action = null;
                    if (NUMBER_LIST.contains(btnText.charAt(0))) {
                        action = new NumericAction(btnText);
                    } else if (".".equals(btnText)) {
                        action = new DotAction(btnText);
                    } else {
                        action = new OperationAction(btnText);
                    }
                    JButton button = new JButton(action);
                    button.setFont(button.getFont().deriveFont(Font.BOLD, FONT_SIZE));
                    buttonPanel.add(button);
                }
            }
        }

        setBorder(BorderFactory.createEmptyBorder(GAP, GAP, GAP, GAP));
        setLayout(new BorderLayout(GAP, GAP));
        add(display, BorderLayout.PAGE_START);
        add(buttonPanel, BorderLayout.CENTER);
    }

    private class NumericAction extends AbstractAction {
        public NumericAction(String name) {
            super(name);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            String text = display.getText();
            text += e.getActionCommand();
            display.setText(text);
        }
    }

    private class DotAction extends AbstractAction {
        public DotAction(String name) {
            super(name);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            String text = display.getText();
            if (text.contains(".")) {
                return; // only one dot allowed
            }
            text += e.getActionCommand();
            display.setText(text);
        }
    }

    private class OperationAction extends AbstractAction {
        public OperationAction(String name) {
            super(name);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            // TODO write code for operations buttons
        }
    }

    private static void createAndShowGui() {
        SimpleCalc mainPanel = new SimpleCalc();

        JFrame frame = new JFrame("SimpleCalc");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.getContentPane().add(mainPanel);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGui();
            }
        });
    }
}
虽然空布局和设置框似乎是让新手喜欢的创建复杂GUI的最简单和最好的方法，但您创建的GUI越多，在使用它们时遇到的困难就越严重。当GUI调整大小时，它们不会调整您的组件的大小，它们是一个需要增强或维护的皇家女巫，当它们放置在滚动窗格中时会完全失败，当在所有平台或屏幕分辨率与原始分辨率不同的情况下查看时，它们看起来非常糟糕

在主GUI中使用BorderLayout，将JTextField BorderLayout.PAGE_放置在开始位置。使用JPanel将JButtons放置在GridLayout中，并将此JPanel放置在主GUI的BorderLayout.CENTER位置

例如，此GUI：

import java.awt.BorderLayout;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;

@SuppressWarnings("serial")
public class SimpleCalc extends JPanel {
    private static final String[][] BTN_TEXTS = {
        {"C", "Del", "X^2", "+"},
        {"7", "8", "9", "-"},
        {"4", "5", "6", "*"},
        {"1", "2", "3", "/"},
        {"0", ".", "", "="}
    };
    private static final int COLS = 12;
    private static final int GAP = 3;
    private static final char[] NUMBER_ARRAY = "0123456789".toCharArray();
    private static final List<Character> NUMBER_LIST = new ArrayList<>();
    private static final float FONT_SIZE = 36f;
    private JTextField display = new JTextField(COLS);

    static {
        for (char c : NUMBER_ARRAY) {
            NUMBER_LIST.add(c);
        }
    }

    public SimpleCalc() {
        display.setFont(display.getFont().deriveFont(FONT_SIZE));
        display.setFocusable(false);

        int rows = BTN_TEXTS.length;
        int cols = BTN_TEXTS[0].length;
        JPanel buttonPanel = new JPanel(new GridLayout(rows, cols, GAP, GAP));
        for (String[] btnTextRow : BTN_TEXTS) {
            for (String btnText : btnTextRow) {
                if (btnText.isEmpty()) {
                    buttonPanel.add(new JLabel());
                } else {
                    Action action = null;
                    if (NUMBER_LIST.contains(btnText.charAt(0))) {
                        action = new NumericAction(btnText);
                    } else if (".".equals(btnText)) {
                        action = new DotAction(btnText);
                    } else {
                        action = new OperationAction(btnText);
                    }
                    JButton button = new JButton(action);
                    button.setFont(button.getFont().deriveFont(Font.BOLD, FONT_SIZE));
                    buttonPanel.add(button);
                }
            }
        }

        setBorder(BorderFactory.createEmptyBorder(GAP, GAP, GAP, GAP));
        setLayout(new BorderLayout(GAP, GAP));
        add(display, BorderLayout.PAGE_START);
        add(buttonPanel, BorderLayout.CENTER);
    }

    private class NumericAction extends AbstractAction {
        public NumericAction(String name) {
            super(name);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            String text = display.getText();
            text += e.getActionCommand();
            display.setText(text);
        }
    }

    private class DotAction extends AbstractAction {
        public DotAction(String name) {
            super(name);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            String text = display.getText();
            if (text.contains(".")) {
                return; // only one dot allowed
            }
            text += e.getActionCommand();
            display.setText(text);
        }
    }

    private class OperationAction extends AbstractAction {
        public OperationAction(String name) {
            super(name);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            // TODO write code for operations buttons
        }
    }

    private static void createAndShowGui() {
        SimpleCalc mainPanel = new SimpleCalc();

        JFrame frame = new JFrame("SimpleCalc");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.getContentPane().add(mainPanel);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGui();
            }
        });
    }
}
可以使用此GUI进行以下操作：

import java.awt.BorderLayout;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;

@SuppressWarnings("serial")
public class SimpleCalc extends JPanel {
    private static final String[][] BTN_TEXTS = {
        {"C", "Del", "X^2", "+"},
        {"7", "8", "9", "-"},
        {"4", "5", "6", "*"},
        {"1", "2", "3", "/"},
        {"0", ".", "", "="}
    };
    private static final int COLS = 12;
    private static final int GAP = 3;
    private static final char[] NUMBER_ARRAY = "0123456789".toCharArray();
    private static final List<Character> NUMBER_LIST = new ArrayList<>();
    private static final float FONT_SIZE = 36f;
    private JTextField display = new JTextField(COLS);

    static {
        for (char c : NUMBER_ARRAY) {
            NUMBER_LIST.add(c);
        }
    }

    public SimpleCalc() {
        display.setFont(display.getFont().deriveFont(FONT_SIZE));
        display.setFocusable(false);

        int rows = BTN_TEXTS.length;
        int cols = BTN_TEXTS[0].length;
        JPanel buttonPanel = new JPanel(new GridLayout(rows, cols, GAP, GAP));
        for (String[] btnTextRow : BTN_TEXTS) {
            for (String btnText : btnTextRow) {
                if (btnText.isEmpty()) {
                    buttonPanel.add(new JLabel());
                } else {
                    Action action = null;
                    if (NUMBER_LIST.contains(btnText.charAt(0))) {
                        action = new NumericAction(btnText);
                    } else if (".".equals(btnText)) {
                        action = new DotAction(btnText);
                    } else {
                        action = new OperationAction(btnText);
                    }
                    JButton button = new JButton(action);
                    button.setFont(button.getFont().deriveFont(Font.BOLD, FONT_SIZE));
                    buttonPanel.add(button);
                }
            }
        }

        setBorder(BorderFactory.createEmptyBorder(GAP, GAP, GAP, GAP));
        setLayout(new BorderLayout(GAP, GAP));
        add(display, BorderLayout.PAGE_START);
        add(buttonPanel, BorderLayout.CENTER);
    }

    private class NumericAction extends AbstractAction {
        public NumericAction(String name) {
            super(name);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            String text = display.getText();
            text += e.getActionCommand();
            display.setText(text);
        }
    }

    private class DotAction extends AbstractAction {
        public DotAction(String name) {
            super(name);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            String text = display.getText();
            if (text.contains(".")) {
                return; // only one dot allowed
            }
            text += e.getActionCommand();
            display.setText(text);
        }
    }

    private class OperationAction extends AbstractAction {
        public OperationAction(String name) {
            super(name);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            // TODO write code for operations buttons
        }
    }

    private static void createAndShowGui() {
        SimpleCalc mainPanel = new SimpleCalc();

        JFrame frame = new JFrame("SimpleCalc");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.getContentPane().add(mainPanel);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGui();
            }
        });
    }
}
我猜您使用的是使用边框布局的JFrame。上面的代码向BorderLayout的中心添加了两个组件，这是不允许的

相反，您应该指定适当的约束：

add (header, BorderLayout.PAGE_NORTH);
add (buttonarea, BorderLayout.CENTER);
如果您没有在框架上使用边框布局，那么您应该这样做。有关更多信息和示例，请阅读上Swing教程的部分

此外，在创建JTextAra时，您应该使用：

written = new JTextArea (row, columns);
为文本区域指定适当的大小。在这种情况下，您可以直接将文本区域添加到框架中：

//add (header, BorderLayout.PAGE_NORTH);
add (written, BorderLayout.PAGE_NORTH);
不需要包装器面板

我猜您使用的是使用边框布局的JFrame。上面的代码向BorderLayout的中心添加了两个组件，这是不允许的

相反，您应该指定适当的约束：

add (header, BorderLayout.PAGE_NORTH);
add (buttonarea, BorderLayout.CENTER);
如果您没有在框架上使用边框布局，那么您应该这样做。有关更多信息和示例，请阅读上Swing教程的部分

此外，在创建JTextAra时，您应该使用：

written = new JTextArea (row, columns);
为文本区域指定适当的大小。在这种情况下，您可以直接将文本区域添加到框架中：

//add (header, BorderLayout.PAGE_NORTH);
add (written, BorderLayout.PAGE_NORTH);
不需要包装器面板