更改标题栏中的文本

Question

我在这一行收到错误:无法解析jFrame

jFrame.setTitle(titleName.getText());





    public void createOption(){
        Option = new JPanel();
        Option.setLayout( null );

         JLabel TitleLabel = new JLabel("Change the company name");
         TitleLabel.setBounds(140, 15, 200, 20);
         Option.add(TitleLabel);
         titleName = new JTextField();
         titleName.setBounds(90,40,260,20);
           Option.add(titleName);

           JButton Change = new JButton("Change New Name");
           Change.setBounds(90,80,150,20);
           Change.addActionListener(this);
           Change.setBackground(Color.white);
           Option.add(Change);

           JButton Exit = new JButton("Exit");
           Exit.setBounds(270,80,80,20);
           Exit.addActionListener(this);
           Exit.setBackground(Color.white);
           Option.add(Exit);

           Change.addActionListener(new ActionListener() { 

                public void actionPerformed(ActionEvent arg0) { 
                    jFrame.setTitle(titleName.getText()); 

                } 
            });

}

Answer 1

您必须具有对JFrame的引用.假设按钮和textBox为控件的名称,你可以这样做

    button.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent arg0) {
            jFrame.setTitle(textBox.getText());

        }
    });

编辑:

这是一个完整的例子

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

import javax.swing.*;

public class JFrameExample {
  public static void main(String[] args) {
    final JFrame jFrame = new JFrame("This is a test");
    jFrame.setSize(400, 150);
    Container content = jFrame.getContentPane();
    content.setBackground(Color.white);
    content.setLayout(new FlowLayout()); 
    final JTextField jTextField = new JTextField("TestTitle");
    content.add(jTextField);
    final JButton button = new JButton("Change");
    button.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent arg0) {
            jFrame.setTitle(jTextField.getText());

        }
    });
    content.add(button);
    jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    jFrame.setVisible(true);
  }