Question

我打算做的是当我按下Enter键时，应用程序会启动按钮btn_teach，然后切换到另一个textfield聚焦的标签页。现在，当我实现它时，它完美地工作如果我手动按下按钮（而不是按Enter）。当我实际按下Enter时，标签会切换回来，但该标签上的文字字段不会聚焦。

tp为JTabbedPane。我的计划是从标签索引1切换到标签索引0并设置txt_send重点

    public void actionPerformed(ActionEvent arg0) 
{
    // TODO Auto-generated method stub
        String say = txt_saypane.getText();
        String ans = txt_anspane.getText();
        //this.clear();

        say = say.replace("\n","");
        ans = ans.replace("\n","");

        this.talk(this.botTeach(say,ans), false);

        tp.setSelectedIndex(0);
}

    public void stateChanged(ChangeEvent arg0) 
{
    // TODO Auto-generated method stub
    int sel = tp.getSelectedIndex();
    if(sel == 0)
        txt_send.requestFocusInWindow();
    if(sel == 1)
        txt_saypane.requestFocusInWindow();
}

public void keyPressed(KeyEvent e) 
        {
            // TODO Auto-generated method stub
            if(e.getKeyCode() == KeyEvent.VK_ENTER)
            {

                if(txt_saypane.isFocusOwner() || txt_anspane.isFocusOwner())
                    btn_teach.doClick();
            }
    }

在KeyListener中切换标签时，通过JTabbedPane更改焦点的正确方法是什么？

Answer 1

要让JButton按下ENTER键，您可以将JButton作为DEFAULT Button框架，而不是使用KeyEvents。你可以写下：

yourFrameObject.getRootPane().setDefaultButton(btn_teach);

写这一行也会使这个JButton按下ENTER键，而不需要为它编写整个KeyListener部分。从此KeyListeners中删除JButton。一旦此JButton为DEFAULT Button，现在按下ENTER键，它将执行在其actionPerformed（）方法中编写的工作。

不要将KeyEvents与Swing一起使用，属于awt，KeyBinding是我们在Swing中使用的。

以下是一个帮助您解决问题的示例程序：

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

public class ButtonTest extends JFrame implements ActionListener
{
    private JTabbedPane tabbedPane;
    private JButton focusButton;
    private JPanel contentPane, tab1, tab2;
    private JTextField textField1, textField2, textField3;

    public ButtonTest()
    {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLocationRelativeTo(null);

        tab1 = new JPanel();
        textField1 = new JTextField(10);
        textField1.requestFocusInWindow();
        tab1.add(textField1);

        tab2 = new JPanel();
        textField2 = new JTextField(10);
        textField3 = new JTextField(10);
        tab2.add(textField2);
        tab2.add(textField3);

        contentPane = new JPanel();
        contentPane.setLayout(new BorderLayout());

        tabbedPane = new JTabbedPane(JTabbedPane.TOP,
                                                JTabbedPane.WRAP_TAB_LAYOUT);
        tabbedPane.addTab("TAB 1", null, tab1, "I am TAB 1");
        tabbedPane.addTab("TAB 2", null, tab2, "I am TAB 2");

        focusButton = new JButton("CHANGE FOCUS");
        //focusButton.addMnemonic(KeyEvent.VK_ENTER); /* You can Add this Line too
                                                      /* , to make it work. But here
                                                       * you have to press ALT + ENTER.
                                                       */
        getRootPane().setDefaultButton(focusButton);
        focusButton.addActionListener(this);

        contentPane.add(tabbedPane, BorderLayout.CENTER);
        contentPane.add(focusButton, BorderLayout.PAGE_END);
        setContentPane(contentPane);
        pack();
        setVisible(true);
    }

    public void actionPerformed(ActionEvent ae)
    {
        if (tabbedPane.getSelectedIndex() == 0)
        {
            tabbedPane.setSelectedIndex(1);
            textField3.requestFocusInWindow();
        }
        else if (tabbedPane.getSelectedIndex() == 1)
        {
            tabbedPane.setSelectedIndex(0);
            textField1.requestFocusInWindow();
        }
    }

    public static void main(String... args)
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            public void run()
            {
                new ButtonTest();
            }
        });
    }
}

在JTabbedPane中的选项卡之间切换时，通过KeyListener更改焦点

1 个答案: