关于写两次的 Java KeyStroke 问题

Question

我使用带有 swing 库的 Java 代码为按钮分配了键盘快捷键。如果我在输入之前单击文本字段，它会写入 2 次。我想写一次。

Java 代码：

    button1 = new JButton("1");
    button1.addActionListener(this);
    button1.setBackground(Color.lightGray);
    //button1 normal number button
    button1.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_1, 0), "button1");
    button1.getActionMap().put("button1", new AbstractAction() {

        @Override
        public void actionPerformed(ActionEvent e) {
            textField.setText(textField.getText() + "1");

        }
    });
    //button1 numpad number button
    button1.getInputMap(button1.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_NUMPAD1, 0), "button1");
    button1.getActionMap().put("button1", new AbstractAction() {

        public void actionPerformed(ActionEvent e) {
            textField.setText(textField.getText() + "1");
        }
    });

public void actionPerformed(ActionEvent actionEvent) {
    if (actionEvent.getActionCommand().equals("1")){
        textField.setText(textField.getText() + "1");
    }
}

sample screenshot

你可以在截图中看到，我在选择文本字段时按了一次按钮 1，但它写了 2 次。

Answer 1

你的最后一个方法看起来多余。

public void actionPerformed(ActionEvent actionEvent) {
if (actionEvent.getActionCommand().equals("1")){
    textField.setText(textField.getText() + "1");
}

Answer 2

好的，所以您有一个文本字段和与您的按钮关联的键绑定，因此当您键入时，文本字段和按钮都会执行并更新文本字段。由于您实际上并不需要可编辑文本字段（因为您通过按钮控制它），所以使文本字段不可编辑。

您还为1 按钮附加了两个操作处理程序。如果你删除

button1.addActionListener(this);

您可能会发现问题不再存在

工作示例

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.ActionMap;
import javax.swing.InputMap;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.KeyStroke;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;

public class Test {

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

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            setLayout(new BorderLayout());
            JTextField field = new JTextField(10);
            field.setEditable(false);
            add(field, BorderLayout.NORTH);

            JPanel pad = new JPanel(new GridLayout(0, 3));

            InputMap inputMap = getInputMap(WHEN_IN_FOCUSED_WINDOW);
            ActionMap actionMap = getActionMap();
            for (int index = 0; index < 10; index++) {
                JButton btn = new JButton();
                Action numAction = new NumberAction(field, index);

                btn.setAction(numAction);

                System.out.println(KeyStroke.getKeyStroke("pressed " + index));

                inputMap.put(KeyStroke.getKeyStroke("pressed " + index), "Pressed-" + index);
                actionMap.put("Pressed-" + index, numAction);

                pad.add(btn);
            }

            add(pad);
        }

    }

    public class NumberAction extends AbstractAction {
        private JTextField field;
        private int number;

        public NumberAction(JTextField field, int number) {
            this.field = field;
            this.number = number;

            putValue(NAME, Integer.toString(number));
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            Document doc = field.getDocument();
            try {
                doc.insertString(doc.getLength(), Integer.toString(number), null);
            } catch (BadLocationException ex) {
                ex.printStackTrace();
            }
        }

    }

}