frame.setResizable（false）无效！它改变窗口大小而不是保持尺寸

Question

frame.setResizable(false);

在我的TestCalculator类中，我的计算器类的JFrame不可复制（不是单词），但它在框架内，底部和右侧添加了一些像素......或者从一个或两个面板中删除一些像素。我不确切知道如何说出来，但是我想让框架成为一个固定的尺寸而没有额外的像素和垃圾。

是的，我确实在另一个网站上询问过，但他们无法帮助我，这是明天早上到期的，我已经工作了大约两个星期，并且昨天让计算器工作了。我一直在谷歌上搜索它，找不到具体的解决方案。

我不确定究竟是什么导致它不能正常行事（呃），但它可能在这段代码中的任何地方，也许是它的顺序，idk。

CALCULATOR CLASS：

public class SimpleArithmeticCalculator extends JPanel implements ActionListener {

 private static final int BTN_ONE = 0;

 private static final int BTN_TWO = 1;

 private static final int BTN_THREE = 2;

 private static final int BTN_DIV = 3;

 private static final int BTN_FOUR = 4;

 private static final int BTN_FIVE = 5;

 private static final int BTN_SIX = 6;

 private static final int BTN_MULT = 7;

 private static final int BTN_SEVEN = 8;

 private static final int BTN_EIGHT = 9;

 private static final int BTN_NINE = 10;

 private static final int BTN_MINUS = 11;

 private static final int BTN_ZERO = 12;

 private static final int BTN_DECIMAL = 13;

 private static final int BTN_POWER = 14;

 private static final int BTN_PLUS = 15;

 private static final int BTN_CLEAR = 16;

 private static final int BTN_PERCENT = 17;

 private static final int BTN_BACKSPACE = 18;

 private static final int BTN_CALC = 19;

 private static final int NUM_BUTTONS = 20;



 private static final int OP_MULT = 0;

 private static final int OP_DIV = 1;

 private static final int OP_PLUS = 2;

 private static final int OP_MINUS = 3;

 private static final int OP_POWER = 4;

 private static final int OP_PERCENT = 5;

 private static char[] buttonTexts = {'7' , '8' , '9' , '/' , '4' ,
            '5' , '6' , '*' , '1' , '2' ,
            '3' , '-' , '0' , '.' , '^' ,
            '+' , 'C' , '%' , '<' , '='};

 private static final int[] buttonKeys = {
  KeyEvent.VK_NUMPAD7 , KeyEvent.VK_NUMPAD8 , KeyEvent.VK_NUMPAD9 , KeyEvent.VK_DIVIDE , KeyEvent.VK_NUMPAD4 ,
  KeyEvent.VK_NUMPAD5 , KeyEvent.VK_NUMPAD6 , KeyEvent.VK_MULTIPLY , KeyEvent.VK_NUMPAD1 , KeyEvent.VK_NUMPAD2 ,
   KeyEvent.VK_NUMPAD3 , KeyEvent.VK_MINUS , KeyEvent.VK_NUMPAD0 , KeyEvent.VK_STOP, '^',
   KeyEvent.VK_PLUS, KeyEvent.VK_C , '%' , KeyEvent.VK_BACK_SPACE , KeyEvent.VK_ENTER
 };

 private Font font;

 private JButton[] buttons;

 private JTextField displayText;

 public JPanel calcPanel;

 private JPanel textPanel;

 private JPanel buttonPanel;

 private String buffer;

 private int op;

 private int opStored;

 private double lhs;

 private double rhs;

 private double rhsStored;

 private boolean left;

 private boolean clear;

 private char lastAction;

    public SimpleArithmeticCalculator() {

      super();

  buffer = new String("0.0");

  op = -1;

  opStored = -1;

  lhs = 0.0;

  rhs = 0.0;

  rhsStored = 0.0;

  left = true;

  clear = true;

  lastAction = '=';

     font = Font.decode("Courier PLAIN 24");

     try {

       UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());

     }

     catch (Exception e) {

     }

  calcPanel = new JPanel();

  textPanel = new JPanel();

  buttonPanel = new JPanel();

  buttonPanel.setForeground(null);

  textPanel.setForeground(null);

  calcPanel.setForeground(null);

  textPanel.setLayout(new GridLayout(1,1,0,0));

  buttonPanel.setLayout(new GridLayout(5 , 10 , 10 , 10));

  displayText = new JTextField("" , 20);

  displayText.setHorizontalAlignment(JTextField.RIGHT);

  displayText.setFont(font);

  displayText.setEditable(false);

  textPanel.add(displayText);

  buttons = new JButton[NUM_BUTTONS];

  for (int i = 0 ; i < NUM_BUTTONS ; ++i) {

    buttons[i] = new JButton("" + buttonTexts[i]);

    buttons[i].setMnemonic(buttonKeys[i]);

    buttons[i].setFont(font);

    buttons[i].setMinimumSize(new Dimension(50,50));

    buttons[i].setActionCommand("" + buttonTexts[i]);

    buttons[i].addActionListener(this);

    buttonPanel.add(buttons[i]);

  }

  buttons[BTN_POWER].setText("^");

  buttons[BTN_PERCENT].setText("%");

  buttonPanel.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));

  textPanel.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));

  calcPanel.setLayout(new BorderLayout());

  calcPanel.add(textPanel , BorderLayout.NORTH);

  calcPanel.add(buttonPanel , BorderLayout.CENTER);

  add(calcPanel);

     for (int i = 0 ; i < NUM_BUTTONS ; ++i) {

       buttons[i].setMaximumSize(buttons[i].getSize());

     }

     }

 public void SetColors(Color bg , Color textbg , Color textcolor) {

   calcPanel.setBackground(bg);

   calcPanel.setVisible(true);

   calcPanel.setOpaque(false);

   buttonPanel.setBackground(bg);

   buttonPanel.setVisible(true);

   buttonPanel.setOpaque(false);

   textPanel.setBackground(bg);

   textPanel.setOpaque(false);

   textPanel.setVisible(true);

   displayText.setBackground(textbg);

   displayText.setForeground(textcolor);

   for (int i = 0 ; i < NUM_BUTTONS ; ++i) {

     buttons[i].setForeground(textcolor);

   }

 }

 public void actionPerformed(ActionEvent ev) {

  String action = ev.getActionCommand();

  char c = action.charAt(0);

  boolean calc = false;

 if (c == buttonTexts[BTN_CLEAR]) {

   buffer = "";

   left = true;

 }

 else if (c == buttonTexts[BTN_BACKSPACE]) {

   if (buffer.length() > 0) {

     buffer = buffer.substring(0 , buffer.length() - 1);

   }

   if (lastAction == buttonTexts[BTN_CALC]) {

     left = true;

   }

   clear = false;

 }

 else if ((c == buttonTexts[BTN_CALC]) || isOpCharacter(c)) {

   int opCurrent = op;

   if (c == buttonTexts[BTN_CALC]) {

    if (!left) {

      calc = true;

      if (isOpCharacter(lastAction)) {

        rhs = GetBufferValue();

        rhsStored = rhs;

        opCurrent = op;

        opStored = op;

      }

      else if (lastAction == buttonTexts[BTN_CALC]) {

      rhs = rhsStored;

      opCurrent = opStored;

      }

      else {

      rhs = GetBufferValue();

      rhsStored = rhs;

      opCurrent = op;

      opStored = op;

      }

    }

   }

   else if (isOpCharacter(c)) {

    opStored = op;

    if (c == buttonTexts[BTN_MULT])  {op = OP_MULT;}

    if (c == buttonTexts[BTN_DIV])   {op = OP_DIV;}

    if (c == buttonTexts[BTN_PLUS])  {op = OP_PLUS;}

    if (c == buttonTexts[BTN_MINUS]) {op = OP_MINUS;}

    if (c == buttonTexts[BTN_POWER])  {op = OP_POWER;}

    if (c == buttonTexts[BTN_PERCENT]) {op = OP_PERCENT;}

    if (lastAction == buttonTexts[BTN_CALC]) {

      lhs = GetBufferValue();

      clear = true;

    }

    else if (isOpCharacter(lastAction)) {

    }

    else {


      if (left) {

        lhs = GetBufferValue();

        left = false;

      }

      else {

        calc = true;

        rhs = GetBufferValue();

        opCurrent = opStored;

        opStored = op;

      }

      clear = true;

    }

   }

   if (calc) {

    double result = 0.0;

    if (opCurrent == OP_MULT)  {result = lhs * rhs;}

    if (opCurrent == OP_DIV)   {result = lhs / rhs;}

    if (opCurrent == OP_PLUS)  {result = lhs + rhs;}

    if (opCurrent == OP_MINUS) {result = lhs - rhs;}

    if (opCurrent == OP_POWER) {result = Math.pow(lhs,rhs);}  

    if (opCurrent == OP_PERCENT) {result = lhs / 100;}

    lhs = result;

    buffer = "" + result;

    clear = true;

   }

  }

 else {

   if (lastAction == buttonTexts[BTN_CALC]) {

    left = true;

   }

   if (clear) {

    buffer = "";

    clear = false;

   }

   if (c == buttonTexts[BTN_DECIMAL]) {

    if (buffer.indexOf('.') == -1) {

     if (buffer.length() == 0 || (buffer.length() == 1 && buffer.charAt(0) == '-')) {

       buffer += "0";

     }

     buffer += ".";

    }

   }

   else if (c == buttonTexts[BTN_ZERO]) {

    if (buffer.length() == 0 || (buffer.length() == 1 && buffer.charAt(0) == '-')) {

      buffer += "0.";

    }

    else if (buffer.length() > 0 && (isNonZeroNumber(buffer.charAt(0)) ||
            (buffer.charAt(0) == '-' && isNonZeroNumber(buffer.charAt(1))))) {

      buffer += "0";

    }

    else if (buffer.compareTo("0") == 0 || buffer.compareTo("-0") == 0) {

    }

    else {

      buffer += "0";

    }

   }

   else {

    if (!buffer.equals("0") && !buffer.equals("-0")) {

      buffer += c;

    }

   }

 }

  lastAction = c;

  displayText.setText(buffer);

 }

 public double GetBufferValue() {

   double d = 0.0;

   try {

     d = Double.parseDouble(buffer);

   }

   catch (NumberFormatException e) {

   System.out.println("NumberFormatException in GetBufferValue()");

   }

   return d;

 }

 public boolean isOpCharacter(char c) {

   return ((c == buttonTexts[BTN_MULT]) ||

           (c == buttonTexts[BTN_DIV]) ||

           (c == buttonTexts[BTN_PLUS]) ||

           (c == buttonTexts[BTN_MINUS]) ||

           (c == buttonTexts[BTN_POWER]) ||

           (c == buttonTexts[BTN_PERCENT]));

 }

 public boolean isNumericCharacter(char c) {

  return ((c == buttonTexts[BTN_ZERO]) ||

    (c == buttonTexts[BTN_ONE]) ||

    (c == buttonTexts[BTN_TWO]) ||

    (c == buttonTexts[BTN_THREE]) ||

    (c == buttonTexts[BTN_FOUR]) ||

    (c == buttonTexts[BTN_FIVE]) ||

    (c == buttonTexts[BTN_SIX]) ||

    (c == buttonTexts[BTN_SEVEN]) ||

    (c == buttonTexts[BTN_EIGHT]) ||

    (c == buttonTexts[BTN_NINE]) ||

    (c == buttonTexts[BTN_DECIMAL]));

 }

 public boolean isNonZeroNumber(char c) {

  return (c == buttonTexts[BTN_ONE] ||

    c == buttonTexts[BTN_TWO] ||

    c == buttonTexts[BTN_THREE] ||

    c == buttonTexts[BTN_FOUR] ||

    c == buttonTexts[BTN_FIVE] ||

    c == buttonTexts[BTN_SIX] ||

    c == buttonTexts[BTN_SEVEN] ||

    c == buttonTexts[BTN_EIGHT] ||

    c == buttonTexts[BTN_NINE]);

 }

    public static void main(String[] args) {

}

}

TEST CLASS：

public class TestCalculator {

  public static void main(String[] args) {

        ImagePanel panel = new ImagePanel(new ImageIcon("01_Crane_AGweb.jpg").getImage());

        SimpleArithmeticCalculator calc = new SimpleArithmeticCalculator();

        JFrame frame = new JFrame("Simple Arithmetic Calculator");

        frame.setResizable(false);   

        frame.getContentPane().add(panel);

        frame.getContentPane().add(calc);

        **frame.setPreferredSize(new Dimension(343,343));**

        frame.pack();

        frame.setVisible(true);      

        **frame.setMinimumSize(new Dimension(343,371));**

        frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);

        panel.setVisible(true);

        panel.setOpaque(true);

        panel.add(calc);

        calc.SetColors(null , Color.white , new Color(72,61,139));

        calc.setVisible(true);

        calc.setOpaque(false);

}

}

class ImagePanel extends JPanel {

  private Image img;

  public ImagePanel(String img) {

    this(new ImageIcon(img).getImage());

  }

  public ImagePanel(Image img) {

    this.img = img;

    Dimension size = new Dimension(img.getWidth(null), img.getHeight(null));

    this.setPreferredSize(new Dimension(size));

    this.setMinimumSize(new Dimension(size));

    this.setMaximumSize(new Dimension(size));

    this.setSize(new Dimension(size));

    **this.setLayout(null);**

  }

    public void paintComponent(Graphics g) {

        super.paintComponent(g);

        g.drawImage(img, 0, 0, this.getWidth(),this.getHeight(),this);

    }

}

Answer 1

框架有边框。如果完成，pack将尝试创建可查看区域（框架边框内的空间）以匹配内容窗格的首选大小。

不要担心框架的大小，而是让两个组件和布局管理器自己做出决定......

第一个值是图像面板/图像的大小，第二个值是窗口的大小。

请务必在致电setResizable ...

之前致电pack

import java.awt.Color;
import java.awt.Dimension;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Window;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class TestCalculator {

    public static void main(String[] args) {
        ImagePanel panel = new ImagePanel(new ImageIcon("/path/to/image").getImage());
        JFrame frame = new JFrame("Simple Arithmetic Calculator");
        frame.getContentPane().add(panel);

        frame.setResizable(false);
        frame.pack();
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

class ImagePanel extends JPanel {

    private Image img;

    public ImagePanel(String img) {
        this(new ImageIcon(img).getImage());
    }

    public ImagePanel(Image img) {
        this.img = img;
        Dimension size = new Dimension(img.getWidth(null), img.getHeight(null));
    }

    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.drawImage(img, 0, 0, this);
        g.setColor(Color.WHITE);
        FontMetrics fm = g.getFontMetrics();
        Window window = SwingUtilities.getWindowAncestor(this);
        int y = fm.getAscent();
        g.drawString(getWidth() + "x" + getHeight() + "; " + window.getWidth() + "x" + window.getHeight(), 0, y);
    }
}

使用简单布局示例进行更新

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.Window;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.EmptyBorder;

public class TestCalculator {

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

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

                ImagePanel panel = new ImagePanel(new ImageIcon("/path/to/image").getImage());
                panel.add(new Calculator());
                JFrame frame = new JFrame("Simple Arithmetic Calculator");
                frame.getContentPane().add(panel);

                frame.setResizable(false);
                frame.pack();
                frame.setVisible(true);
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            }
        });
    }

    public class Calculator extends JPanel {

        public Calculator() {
            setOpaque(false);
            setLayout(new BorderLayout());

            add(new JTextField(), BorderLayout.NORTH);

            JPanel keysPane = new JPanel(new GridLayout(5, 4, 8, 8));
            keysPane.setBorder(new EmptyBorder(4, 0, 0, 4));
            keysPane.setOpaque(false);
            String keys[] = new String[]{
                "7", "8", "9", "/",
                "4", "5", "6", "*",
                "1", "2", "3", "-",
                "0", ".", "^", "+",
                "C", "%", "<", "=",
            };
            for (String key : keys) {
                keysPane.add(new JButton(key));
            }
            add(keysPane);
        }

    }

    class ImagePanel extends JPanel {

        private Image img;

        public ImagePanel(String img) {
            this(new ImageIcon(img).getImage());
        }

        public ImagePanel(Image img) {
            this.img = img;
            Dimension size = new Dimension(img.getWidth(null), img.getHeight(null));
            this.setPreferredSize(new Dimension(size));
            setLayout(new BorderLayout());
            setBorder(new EmptyBorder(16, 16, 16, 16));
        }

        public void paintComponent(Graphics g) {
            super.paintComponent(g);
            g.drawImage(img, 0, 0, this);
            g.setColor(Color.WHITE);
            FontMetrics fm = g.getFontMetrics();
            Window window = SwingUtilities.getWindowAncestor(this);
            int y = fm.getAscent();
            g.drawString(getWidth() + "x" + getHeight() + "; " + window.getWidth() + "x" + window.getHeight(), 0, y);
        }
    }

}

从扩展示例更新

你做事的顺序非常重要。一般来说，您希望初始化界面，添加所需的所有组件，打包框架并使其可见......

这通常不是你在做什么。而不是像......那样做。

ImagePanel panel = new ImagePanel(new ImageIcon("01_Crane_AGweb.jpg").getImage());
SimpleArithmeticCalculator calc = new SimpleArithmeticCalculator();

JFrame frame = new JFrame("Simple Arithmetic Calculator");

frame.setResizable(false);   
// This is not going to come out well, as BorderLayout
// will only allow a single component to occupy the CenterPosition
frame.getContentPane().add(panel);
frame.getContentPane().add(calc);
frame.setPreferredSize(new Dimension(343,343));
// Now sized to the preferred size of the calc pane...
frame.pack();
frame.setVisible(true);      
frame.setMinimumSize(new Dimension(343,371));
frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
// Rather pointless as Swing components are visible by default...
panel.setVisible(true);
panel.setOpaque(true);
// This is now going to change the preferred size of the window...
panel.add(calc);

你可以做更像......的事情。

ImagePanel panel = new ImagePanel(new ImageIcon("01_Crane_AGweb.jpg").getImage());
SimpleArithmeticCalculator calc = new SimpleArithmeticCalculator();

JFrame frame = new JFrame("Simple Arithmetic Calculator");

panel.setVisible(true);
panel.setOpaque(true);
panel.add(calc);
frame.getContentPane().add(panel);

frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);   
frame.pack();
frame.setVisible(true);      

，而不是...

完整运行示例...

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class TestCalculator100 {

    public static void main(String[] args) {
        new TestCalculator100();
    }

    public TestCalculator100() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                ImagePanel panel = new ImagePanel(new ImageIcon("01_Crane_AGweb.jpg").getImage());

                SimpleArithmeticCalculator calc = new SimpleArithmeticCalculator();
                calc.setOpaque(false);
                panel.add(calc);

                JFrame frame = new JFrame("Simple Arithmetic Calculator");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.getContentPane().add(panel);
                frame.setResizable(false);
                frame.pack();
                frame.setVisible(true);

            }

        });
    }

    class ImagePanel extends JPanel {

        private Image img;

        public ImagePanel(String img) {

            this(new ImageIcon(img).getImage());

        }

        public ImagePanel(Image img) {

            this.img = img;

            Dimension size = new Dimension(img.getWidth(null), img.getHeight(null));
        }

        @Override
        public void paintComponent(Graphics g) {

            super.paintComponent(g);

            g.drawImage(img, 0, 0, this.getWidth(), this.getHeight(), this);

        }
    }

    public static class SimpleArithmeticCalculator extends JPanel implements ActionListener {

        private static final int BTN_ONE = 0;

        private static final int BTN_TWO = 1;

        private static final int BTN_THREE = 2;

        private static final int BTN_DIV = 3;

        private static final int BTN_FOUR = 4;

        private static final int BTN_FIVE = 5;

        private static final int BTN_SIX = 6;

        private static final int BTN_MULT = 7;

        private static final int BTN_SEVEN = 8;

        private static final int BTN_EIGHT = 9;

        private static final int BTN_NINE = 10;

        private static final int BTN_MINUS = 11;

        private static final int BTN_ZERO = 12;

        private static final int BTN_DECIMAL = 13;

        private static final int BTN_POWER = 14;

        private static final int BTN_PLUS = 15;

        private static final int BTN_CLEAR = 16;

        private static final int BTN_PERCENT = 17;

        private static final int BTN_BACKSPACE = 18;

        private static final int BTN_CALC = 19;

        private static final int NUM_BUTTONS = 20;

        private static final int OP_MULT = 0;

        private static final int OP_DIV = 1;

        private static final int OP_PLUS = 2;

        private static final int OP_MINUS = 3;

        private static final int OP_POWER = 4;

        private static final int OP_PERCENT = 5;

        private static char[] buttonTexts = {'7', '8', '9', '/', '4',
            '5', '6', '*', '1', '2',
            '3', '-', '0', '.', '^',
            '+', 'C', '%', '<', '='};

        private static final int[] buttonKeys = {
            KeyEvent.VK_NUMPAD7, KeyEvent.VK_NUMPAD8, KeyEvent.VK_NUMPAD9, KeyEvent.VK_DIVIDE, KeyEvent.VK_NUMPAD4,
            KeyEvent.VK_NUMPAD5, KeyEvent.VK_NUMPAD6, KeyEvent.VK_MULTIPLY, KeyEvent.VK_NUMPAD1, KeyEvent.VK_NUMPAD2,
            KeyEvent.VK_NUMPAD3, KeyEvent.VK_MINUS, KeyEvent.VK_NUMPAD0, KeyEvent.VK_STOP, '^',
            KeyEvent.VK_PLUS, KeyEvent.VK_C, '%', KeyEvent.VK_BACK_SPACE, KeyEvent.VK_ENTER
        };

        private Font font;

        private JButton[] buttons;

        private JTextField displayText;

        public JPanel calcPanel;

        private JPanel textPanel;

        private JPanel buttonPanel;

        private String buffer;

        private int op;

        private int opStored;

        private double lhs;

        private double rhs;

        private double rhsStored;

        private boolean left;

        private boolean clear;

        private char lastAction;

        public SimpleArithmeticCalculator() {

            super();

            buffer = new String("0.0");

            op = -1;

            opStored = -1;

            lhs = 0.0;

            rhs = 0.0;

            rhsStored = 0.0;

            left = true;

            clear = true;

            lastAction = '=';

            font = Font.decode("Courier PLAIN 24");

            try {

                UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());

            } catch (Exception e) {

            }

            calcPanel = new JPanel();
            calcPanel.setOpaque(false);

            textPanel = new JPanel();
            textPanel.setOpaque(false);

            buttonPanel = new JPanel();
            buttonPanel.setOpaque(false);

            textPanel.setLayout(new GridLayout(1, 1, 0, 0));

            buttonPanel.setLayout(new GridLayout(5, 10, 10, 10));

            displayText = new JTextField("", 20);

            displayText.setHorizontalAlignment(JTextField.RIGHT);

            displayText.setFont(font);

            displayText.setEditable(false);

            textPanel.add(displayText);

            buttons = new JButton[NUM_BUTTONS];

            for (int i = 0; i < NUM_BUTTONS; ++i) {

                buttons[i] = new JButton("" + buttonTexts[i]);

                buttons[i].setMnemonic(buttonKeys[i]);

                buttons[i].setFont(font);

                buttons[i].setMinimumSize(new Dimension(50, 50));

                buttons[i].setActionCommand("" + buttonTexts[i]);

                buttons[i].addActionListener(this);

                buttonPanel.add(buttons[i]);

            }

            buttons[BTN_POWER].setText("^");

            buttons[BTN_PERCENT].setText("%");

            buttonPanel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));

            textPanel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));

            calcPanel.setLayout(new BorderLayout());

            calcPanel.add(textPanel, BorderLayout.NORTH);

            calcPanel.add(buttonPanel, BorderLayout.CENTER);

            add(calcPanel);

            for (int i = 0; i < NUM_BUTTONS; ++i) {

                buttons[i].setMaximumSize(buttons[i].getSize());

            }

        }

        public void SetColors(Color bg, Color textbg, Color textcolor) {

            calcPanel.setBackground(bg);

            calcPanel.setVisible(true);

            calcPanel.setOpaque(false);

            buttonPanel.setBackground(bg);

            buttonPanel.setVisible(true);

            buttonPanel.setOpaque(false);

            textPanel.setBackground(bg);

            textPanel.setOpaque(false);

            textPanel.setVisible(true);

            displayText.setBackground(textbg);

            displayText.setForeground(textcolor);

            for (int i = 0; i < NUM_BUTTONS; ++i) {

                buttons[i].setForeground(textcolor);

            }

        }

        public void actionPerformed(ActionEvent ev) {

            String action = ev.getActionCommand();

            char c = action.charAt(0);

            boolean calc = false;

            if (c == buttonTexts[BTN_CLEAR]) {

                buffer = "";

                left = true;

            } else if (c == buttonTexts[BTN_BACKSPACE]) {

                if (buffer.length() > 0) {

                    buffer = buffer.substring(0, buffer.length() - 1);

                }

                if (lastAction == buttonTexts[BTN_CALC]) {

                    left = true;

                }

                clear = false;

            } else if ((c == buttonTexts[BTN_CALC]) || isOpCharacter(c)) {

                int opCurrent = op;

                if (c == buttonTexts[BTN_CALC]) {

                    if (!left) {

                        calc = true;

                        if (isOpCharacter(lastAction)) {

                            rhs = GetBufferValue();

                            rhsStored = rhs;

                            opCurrent = op;

                            opStored = op;

                        } else if (lastAction == buttonTexts[BTN_CALC]) {

                            rhs = rhsStored;

                            opCurrent = opStored;

                        } else {

                            rhs = GetBufferValue();

                            rhsStored = rhs;

                            opCurrent = op;

                            opStored = op;

                        }

                    }

                } else if (isOpCharacter(c)) {

                    opStored = op;

                    if (c == buttonTexts[BTN_MULT]) {
                        op = OP_MULT;
                    }

                    if (c == buttonTexts[BTN_DIV]) {
                        op = OP_DIV;
                    }

                    if (c == buttonTexts[BTN_PLUS]) {
                        op = OP_PLUS;
                    }

                    if (c == buttonTexts[BTN_MINUS]) {
                        op = OP_MINUS;
                    }

                    if (c == buttonTexts[BTN_POWER]) {
                        op = OP_POWER;
                    }

                    if (c == buttonTexts[BTN_PERCENT]) {
                        op = OP_PERCENT;
                    }

                    if (lastAction == buttonTexts[BTN_CALC]) {

                        lhs = GetBufferValue();

                        clear = true;

                    } else if (isOpCharacter(lastAction)) {

                    } else {

                        if (left) {

                            lhs = GetBufferValue();

                            left = false;

                        } else {

                            calc = true;

                            rhs = GetBufferValue();

                            opCurrent = opStored;

                            opStored = op;

                        }

                        clear = true;

                    }

                }

                if (calc) {

                    double result = 0.0;

                    if (opCurrent == OP_MULT) {
                        result = lhs * rhs;
                    }

                    if (opCurrent == OP_DIV) {
                        result = lhs / rhs;
                    }

                    if (opCurrent == OP_PLUS) {
                        result = lhs + rhs;
                    }

                    if (opCurrent == OP_MINUS) {
                        result = lhs - rhs;
                    }

                    if (opCurrent == OP_POWER) {
                        result = Math.pow(lhs, rhs);
                    }

                    if (opCurrent == OP_PERCENT) {
                        result = lhs / 100;
                    }

                    lhs = result;

                    buffer = "" + result;

                    clear = true;

                }

            } else {

                if (lastAction == buttonTexts[BTN_CALC]) {

                    left = true;

                }

                if (clear) {

                    buffer = "";

                    clear = false;

                }

                if (c == buttonTexts[BTN_DECIMAL]) {

                    if (buffer.indexOf('.') == -1) {

                        if (buffer.length() == 0 || (buffer.length() == 1 && buffer.charAt(0) == '-')) {

                            buffer += "0";

                        }

                        buffer += ".";

                    }

                } else if (c == buttonTexts[BTN_ZERO]) {

                    if (buffer.length() == 0 || (buffer.length() == 1 && buffer.charAt(0) == '-')) {

                        buffer += "0.";

                    } else if (buffer.length() > 0 && (isNonZeroNumber(buffer.charAt(0))
                            || (buffer.charAt(0) == '-' && isNonZeroNumber(buffer.charAt(1))))) {

                        buffer += "0";

                    } else if (buffer.compareTo("0") == 0 || buffer.compareTo("-0") == 0) {

                    } else {

                        buffer += "0";

                    }

                } else {

                    if (!buffer.equals("0") && !buffer.equals("-0")) {

                        buffer += c;

                    }

                }

            }

            lastAction = c;

            displayText.setText(buffer);

        }

        public double GetBufferValue() {

            double d = 0.0;

            try {

                d = Double.parseDouble(buffer);

            } catch (NumberFormatException e) {

                System.out.println("NumberFormatException in GetBufferValue()");

            }

            return d;

        }

        public boolean isOpCharacter(char c) {

            return ((c == buttonTexts[BTN_MULT])
                    || (c == buttonTexts[BTN_DIV])
                    || (c == buttonTexts[BTN_PLUS])
                    || (c == buttonTexts[BTN_MINUS])
                    || (c == buttonTexts[BTN_POWER])
                    || (c == buttonTexts[BTN_PERCENT]));

        }

        public boolean isNumericCharacter(char c) {

            return ((c == buttonTexts[BTN_ZERO])
                    || (c == buttonTexts[BTN_ONE])
                    || (c == buttonTexts[BTN_TWO])
                    || (c == buttonTexts[BTN_THREE])
                    || (c == buttonTexts[BTN_FOUR])
                    || (c == buttonTexts[BTN_FIVE])
                    || (c == buttonTexts[BTN_SIX])
                    || (c == buttonTexts[BTN_SEVEN])
                    || (c == buttonTexts[BTN_EIGHT])
                    || (c == buttonTexts[BTN_NINE])
                    || (c == buttonTexts[BTN_DECIMAL]));

        }

        public boolean isNonZeroNumber(char c) {

            return (c == buttonTexts[BTN_ONE]
                    || c == buttonTexts[BTN_TWO]
                    || c == buttonTexts[BTN_THREE]
                    || c == buttonTexts[BTN_FOUR]
                    || c == buttonTexts[BTN_FIVE]
                    || c == buttonTexts[BTN_SIX]
                    || c == buttonTexts[BTN_SEVEN]
                    || c == buttonTexts[BTN_EIGHT]
                    || c == buttonTexts[BTN_NINE]);

        }

    }
}

Answer 2

  

我在这个网站上只发了三个问题，没有一个专门关于frame.setResizable（false）;在此之前！

我知道这是关于setResizable（）方法的第一个问题。我说setResizable（）方法没有按照你期望的方式工作，因为你的代码都搞砸了，因为你没有听过你过去给出的建议。如果您已经听过建议，那么使用setResizable（false）就不会有问题。

frame.getContentPane().add(panel);           
frame.getContentPane().add(calc);
frame.setPreferredSize(new Dimension(358,379));
frame.pack();
...
panel.add(calc);

您可以将“面板”和“计算”添加到内容窗格中。您明确告知JFrame的默认布局是BorderLayout，并且您不能向CENTER添加两个面板（当您未指定约束时这是默认布局）

然后打包（）框架并将“calc”添加到“panel”。这正在改变框架中组件的结构。再次告诉你，在执行pack（）之前必须将所有组件添加到框架中。

然后给出了关于如何使用带有图像作为背景的面板以及如何将“背景面板”添加到框架并将“计算面板”添加到背景中的建议。所有这些代码都非常简单如您所示，使用适当的布局管理器。

您的代码现在已经搞砸了，因为您正在硬编码各处的首选，最小和最大尺寸。您的尺寸可能会考虑图像的大小，但它们没有考虑标题栏的大小和框架周围的边框，因此setResizable（false）方法无法正常工作。

如果您使用布局管理器，就像您在其他帖子中所展示的那样，您无需在类中的任何位置使用硬代码大小，并且无论您是否使用setRisizable（false），代码都将完全相同。

另外，昨天我告诉你不需要以下陈述：

panel.setVisible(true);
calc.setVisible(true);

因为默认情况下它们已经可见。但你仍然包括这些陈述。现在这不会引起问题，但它只是表明你听我的建议很少。