我似乎无法使这种继承起作用

Question

I have a tabbed application. One of the tabs you can enter the name of the company and it should change it to whatever you typed into the other tab. Here are both classes.

On this code its telling me to change About.setCompanyName(str); to static

The error that I am seeing is "Cannot make a static reference to the non-static method SetCompanyName(String) from the type About"

package CourseProject;

import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.*;

import javax.swing.*;

public class Options extends JPanel{

    private JLabel changeLabel;
    private JTextField changeName;
    private JButton setName;
    private JButton exitButton;

    public Options(){
        GridBagLayout gridbag = new GridBagLayout();
        GridBagConstraints c = new GridBagConstraints();
        c.fill = GridBagConstraints.NORTH;
        setBackground(Color.WHITE);
        super.setLayout(gridbag);
        c.insets = new Insets(10, 10, 10, 10);

        changeLabel = new JLabel("Change Company Name:");
        changeName = new JTextField("", 10);
        setName = new JButton("Set New Name");
        exitButton = new JButton("Exit");       

        c.gridx = 0;
        c.gridy = 0;
        c.gridwidth = 2;
        add(changeLabel, c);        

        c.gridx = 0;
        c.gridy = 1;    
        add(changeName, c);     

        c.gridx = 0;
        c.gridy = 2;
        c.gridwidth = 1;
        add(setName, c);
        setName.addActionListener(new setNameAction());

        c.gridx = 1;
        c.gridy = 2;    
        add(exitButton, c);
        exitButton.addActionListener(new exitApp());
        exitButton.setSize(40,40);      
    }
    class setNameAction implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {

            String str;
            str = changeName.getText();
            About.SetCompanyName(str);
            changeName.setText("");
        }

    }
    class exitApp implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            System.exit(0);
        }
    }
}

And here is "About" which contains my setter. It asks me to make the method and variable static but I know this wont work because I am wanting to change it

package CourseProject;

import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;

import javax.swing.JLabel;
import javax.swing.JPanel;

public class About extends JPanel{

    private JLabel programInfoLabel;
    private JLabel programInfo;
    private JLabel programmerLabel;
    private JLabel programmer;
    private JLabel companyLabel;
    JLabel company;
    public String companyName = "enter a company name in options";

    public About() {        

        GridBagLayout gridbag = new GridBagLayout();
        GridBagConstraints c = new GridBagConstraints();
        c.fill = GridBagConstraints.NORTH;
        setBackground(Color.WHITE);
        super.setLayout(gridbag);
        c.insets = new Insets(10, 10, 10, 10);

        programInfoLabel = new JLabel("Program Information:");
        programInfo = new JLabel("This is the CIS355A course project application");
        programmerLabel = new JLabel("Programmer:");
        programmer = new JLabel("Kevin Rankin");
        companyLabel = new JLabel("Company Name:");
        company = new JLabel(companyName);

        c.gridx = 0;
        c.gridy = 0;    
        add(programInfoLabel, c);

        c.gridx = 1;
        c.gridy = 0;    
        add(programInfo, c);

        c.gridx = 0;
        c.gridy = 1;
        add(programmerLabel, c);

        c.gridx = 1;
        c.gridy = 1;
        add(programmer, c);

        c.gridx = 0;
        c.gridy = 2;
        add(companyLabel, c);

        c.gridx = 1;
        c.gridy = 2;
        add(company, c);
    }
    public void SetCompanyName(String str){
        company.setText(str);
    }   
}

Answer 1

On this line

About.SetCompanyName(str);

You're calling SetCompanyName statically (by using the class name "About"). You should either make the method static (which is not the same as "final"; you seem to be confused about this) or create an instance of the About class first, like so:

About myAboutObject = new About();
myAboutObject.SetCompanyName(str);