Question

我试图在一个小程序中创建，当我选择一个复选框时，为特定按钮执行的操作将被更改为执行的另一个操作，让我们说按钮执行的动作给出了1 + 2的结果，我希望当我勾选复选框以使按钮动作执行时只是例如。

这是我的代码

import java.awt.*;

public class frame extends JFrame { // Declaring the frame class

public frame() { // crating a constructor 
    getContentPane().setLayout(new GridLayout(5,2)); // Creating 5 lines and 2 rows
    // first label for adding the first number
    JLabel label = new JLabel("First Number");
    getContentPane().add(label);
    label.setHorizontalAlignment(SwingConstants.CENTER);
    // first text field
    final JTextField text = new JTextField(8);
    getContentPane().add(text);
    text.setHorizontalAlignment(SwingConstants.CENTER);
    // second label for adding second number
    JLabel label1 = new JLabel("Second Number");
    getContentPane().add(label1);
    label1.setHorizontalAlignment(SwingConstants.CENTER);
    // second text field
    final JTextField text1 = new JTextField();
    getContentPane().add(text1);
    text1.setHorizontalAlignment(SwingConstants.CENTER);
    // third label for the result
    JLabel label2 = new JLabel("Result is");
    getContentPane().add(label2);
    label2.setHorizontalAlignment(SwingConstants.CENTER);
    // third text field to show the result
    final JTextField text2 = new JTextField();
    getContentPane().add(text2);
    text2.setHorizontalAlignment(SwingConstants.CENTER);
    text2.setEditable(false);
    // Calculation button
    JButton btn = new JButton("Calculate");
    btn.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            String number1, number2, result, ans;
            try {
                /*number1 = Double.parseDouble(text.getText());
                number2 = Double.parseDouble(text1.getText());
                result = number1*number2;
                text2.setText(Double.toString(result));*/
                if (text.getText().isEmpty() || text1.getText().isEmpty()) {
                    throw new Exception();
                }

                number1 = text.getText();
                number2 = text1.getText();
                result = number1.concat(number2);
                text2.toString();
                text2.setText(result);

            } catch (Exception e1) {
                JOptionPane.showMessageDialog(null, "Please add a letter");
            }
        }
    });     
    getContentPane().add(btn);
    // Clear button
    JButton clear = new JButton("Clear");
    getContentPane().add(clear);

    final JCheckBox chckbxNewCheckBox = new JCheckBox("New check box");
    getContentPane().add(chckbxNewCheckBox);

    final JCheckBox chckbxNewCheckBox_1 = new JCheckBox("New check box");
    getContentPane().add(chckbxNewCheckBox_1);

    chckbxNewCheckBox.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            if (chckbxNewCheckBox.isSelected()) {
                chckbxNewCheckBox_1.setSelected(false);
            }
        }
    });

    chckbxNewCheckBox_1.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            if (chckbxNewCheckBox_1.isSelected()) {
                chckbxNewCheckBox.setSelected(false);
            }
        }
    });

    clear.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            try {
                text.setText("");
                text1.setText("");
                text2.setText("");
            } catch(Exception e1) {
            }
        }
    });

    //setVisible(true);
    //setSize(400,200);
    //setResizable(false);
    //setLocationRelativeTo(null);
    //setTitle("Calculator");
}

public static void main (String args[]) { // Creating the main method
    frame frame = new frame(); // creating an object of the ShowGridLayout class, object is frame.
    frame.setVisible(true);
    frame.setSize(400, 200);
    frame.setResizable(false);
    frame.setLocationRelativeTo(null);
    frame.setTitle("Calculator");
    frame.setDefaultCloseOperation(EXIT_ON_CLOSE);;
}

}

Answer 1

可以通过多种方式解决。

您可以拥有一个整数字段（成员变量或静态），并在选择不同的复选框时更新它的值。为要执行的每种操作定义不同的方法，并通过查看静态整数的值在按钮操作侦听器中调用它们。

OR

保持对添加到按钮的ActionListener的引用，并选中复选框从按钮中删除现有的动作侦听器并添加新的动作侦听器并更新对新侦听器的引用。

我希望它有所帮助。

编辑1：如果您只想一次选择一个选项，最好使用单选按钮。

编辑2：在这里，您可以使用单选按钮以及删除和添加侦听器来执行此操作。

    public class frame extends JFrame { // Declaring the frame class
        final JTextField text;
        final JTextField text1;
        final JTextField text2;

        public frame() { // crating a constructor
            getContentPane().setLayout(new GridLayout(5, 2)); // Creating 5 lines and 2 rows
            // first label for adding the first number
            JLabel label = new JLabel("First Number");
            getContentPane().add(label);
            label.setHorizontalAlignment(SwingConstants.CENTER);
            // first text field
            text = new JTextField(8);
            getContentPane().add(text);
            text.setHorizontalAlignment(SwingConstants.CENTER);
            // second label for adding second number
            JLabel label1 = new JLabel("Second Number");
            getContentPane().add(label1);
            label1.setHorizontalAlignment(SwingConstants.CENTER);
            // second text field
            text1 = new JTextField();
            getContentPane().add(text1);
            text1.setHorizontalAlignment(SwingConstants.CENTER);
            // third label for the result
            JLabel label2 = new JLabel("Result is");
            getContentPane().add(label2);
            label2.setHorizontalAlignment(SwingConstants.CENTER);
            // third text field to show the result
            text2 = new JTextField();
            getContentPane().add(text2);
            text2.setHorizontalAlignment(SwingConstants.CENTER);
            text2.setEditable(false);

            final AddValuesActionListener actionListener = new AddValuesActionListener();
            // Calculation button
            final JButton btn = new JButton("Calculate");
            btn.addActionListener(actionListener);

            final JRadioButton addRadioButton = new JRadioButton("Add", true);
            addRadioButton.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    btn.removeActionListener(actionListener);
                    btn.addActionListener(new AddValuesActionListener());
                }
            });

            final JRadioButton subtractRadioButton = new JRadioButton("Subtract", true);
            subtractRadioButton.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    btn.removeActionListener(actionListener);
                    btn.addActionListener(new SubtractValuesActionListener());
                }
            });


            getContentPane().add(btn);
            // Clear button
            JButton clear = new JButton("Clear");
            getContentPane().add(clear);

            ButtonGroup radioButtons = new ButtonGroup();
            radioButtons.add(addRadioButton);
            radioButtons.add(subtractRadioButton);
            getContentPane().add(addRadioButton);
            getContentPane().add(subtractRadioButton);
        }

        public static void main(String args[]) { // Creating the main method
            frame frame = new frame(); // creating an object of the ShowGridLayout class, object is frame.
            frame.setVisible(true);
            frame.setSize(400, 200);
            frame.setResizable(false);
            frame.setLocationRelativeTo(null);
            frame.setTitle("Calculator");
            frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
            ;
        }

        private class AddValuesActionListener implements ActionListener {
            public void actionPerformed(ActionEvent e) {
                text2.setText(text.getText() + "+" + text1.getText());  //Create add values method
            }
        }

        private class SubtractValuesActionListener implements ActionListener {
            public void actionPerformed(ActionEvent e) {
                text2.setText(text.getText() + "-" + text1.getText());  //Create add values method
            }
        }
    }

以下是您可以通过检查@JeriesHG

    public class frame extends JFrame { // Declaring the frame class
        final JTextField text;
        final JTextField text1;
        final JTextField text2;

        public frame() { // crating a constructor
            getContentPane().setLayout(new GridLayout(5, 2)); // Creating 5 lines and 2 rows
            // first label for adding the first number
            JLabel label = new JLabel("First Number");
            getContentPane().add(label);
            label.setHorizontalAlignment(SwingConstants.CENTER);
            // first text field
            text = new JTextField(8);
            getContentPane().add(text);
            text.setHorizontalAlignment(SwingConstants.CENTER);
            // second label for adding second number
            JLabel label1 = new JLabel("Second Number");
            getContentPane().add(label1);
            label1.setHorizontalAlignment(SwingConstants.CENTER);
            // second text field
            text1 = new JTextField();
            getContentPane().add(text1);
            text1.setHorizontalAlignment(SwingConstants.CENTER);
            // third label for the result
            JLabel label2 = new JLabel("Result is");
            getContentPane().add(label2);
            label2.setHorizontalAlignment(SwingConstants.CENTER);
            // third text field to show the result
            text2 = new JTextField();
            getContentPane().add(text2);
            text2.setHorizontalAlignment(SwingConstants.CENTER);
            text2.setEditable(false);

            final JRadioButton addRadioButton = new JRadioButton("Add", true);
            final JRadioButton subtractRadioButton = new JRadioButton("Subtract", true);

            // Calculation button
            final JButton btn = new JButton("Calculate");
            btn.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                  if (addRadioButton.isSelected()) {
                      text2.setText(text.getText() + "+" + text1.getText());  //Create add values method
                  }     else if (subtractRadioButton.isSelected()) {
                      text2.setText(text.getText() + "-" + text1.getText());  //Create subtract values method
                  }
                }
            });

            getContentPane().add(btn);
            // Clear button
            JButton clear = new JButton("Clear");
            getContentPane().add(clear);

            ButtonGroup radioButtons = new ButtonGroup();
            radioButtons.add(addRadioButton);
            radioButtons.add(subtractRadioButton);
            getContentPane().add(addRadioButton);
            getContentPane().add(subtractRadioButton);
        }

        public static void main(String args[]) { // Creating the main method
            frame frame = new frame(); // creating an object of the ShowGridLayout class, object is frame.
            frame.setVisible(true);
            frame.setSize(400, 200);
            frame.setResizable(false);
            frame.setLocationRelativeTo(null);
            frame.setTitle("Calculator");
            frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
            ;
        }

    }

Answer 2

让我看看我是否完全理解，按钮的动作取决于复选框？如果这是正确的，那么你可以为复选框值设置一个布尔值，或者只检查＆＃34; isSelected＆＃34;函数和动作执行方法，我只是做一个布尔检查并执行我需要的方法。

JButton btn = new JButton("Calculate");
btn.addActionListener(new ActionListener() {
 if(chckbxNewCheckBox.isSelected()){
  //do something here
 }else{
  //do this
 }
}

编辑：我也会执行＆＃34;动作＆＃34;分离方法中的按钮，以便重用代码。（在我要求在另一个按钮或类似的东西中使用相同的方法的情况下）。

复选框以更改按钮actionlistener

2 个答案: