用swing开发的小键盘怎么触发和显示在JOptionPane.showInputDialog弹出的窗口

可以通过继承JOptionPane类，重写createDialog()方法，在该方法中添加自定义的小键盘组件，然后在调用JOptionPane.showInputDialog()时传入自定义的JOptionPane子类对象即可。

以下是一个简单的示例代码：

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class CustomInputDialog extends JOptionPane {

    private JPanel keyboardPanel;
    private JTextField inputField;

    public CustomInputDialog(Component parentComponent, Object message, String title, int messageType) {
        super(message, messageType);
        this.inputField = new JTextField();
        this.keyboardPanel = createKeyboardPanel();

        setInputValue(inputField);
        setMessage(new Object[] {message, inputField});

        JDialog dialog = createDialog(parentComponent, title);
        dialog.setContentPane(keyboardPanel);
        dialog.pack();
        dialog.setVisible(true);
    }

    private JPanel createKeyboardPanel() {
        JPanel panel = new JPanel(new BorderLayout());

        // 添加自定义的小键盘组件
        KeyboardPanel keyboard = new KeyboardPanel();
        keyboard.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                inputField.setText(inputField.getText() + e.getActionCommand());
            }
        });
        panel.add(keyboard, BorderLayout.CENTER);

        return panel;
    }

    public static String showCustomInputDialog(Component parentComponent, Object message, String title, int messageType) {
        CustomInputDialog pane = new CustomInputDialog(parentComponent, message, title, messageType);
        pane.setWantsInput(true);
        pane.selectInitialValue();
        return (String) pane.getInputValue();
    }

    public static void main(String[] args) {
        String input = showCustomInputDialog(null, "Please input something:", "Input", JOptionPane.PLAIN_MESSAGE);
        System.out.println("Input value: " + input);
    }
}

其中，KeyboardPanel是一个自定义的小键盘面板，可以根据具体需求进行实现。在showCustomInputDialog()方法中，创建自定义的CustomInputDialog对象，并将其作为参数传入到JOptionPane.showInputDialog()方法中。最后，通过CustomInputDialog.getInputValue()方法获取用户输入的值。