我似乎無法得到這個繼承工作

Question

我有一個選項卡式應用程序。其中一個選項卡可以輸入公司的名稱，它應該將其更改爲輸入到其他選項卡中的任何內容。這裏有兩個類。

這段代碼告訴我改變About.setCompanyName（str）;靜態

，我看到的是錯誤

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); 
     } 
    } 
} 

在這裏，「不能從類型關於使靜態參考非靜態方法SetCompanyName（字符串）」是「關於」，它包含了我二傳手。它要求我做的方法和靜態變量，但我知道這不會工作，因爲我想改變它

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

在此行中

About.SetCompanyName(str); 

你靜態調用SetCompanyName（通過使用類名稱「關於」）。您應該做的方法靜態的（這是不一樣的「最終」，你似乎混淆了這一點）或第一次創建關於類的一個實例，像這樣：

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