非靜態方法的getContentPane（）不能從靜態上下文錯誤中的Java Swing引用

Question

非靜態方法的getContentPane（）不能從靜態上下文錯誤中的Java Swing

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

public class Studentlogin extends JFrame{ 
    public static void main(String[] args) { 

    Container c = getContentPane(); 

    setTitle(" Staff Signin "); 
    setSize(400 , 300); 
    setLayout(new FlowLayout());  
    setVisible(true); 
    setLayout(null); 

    JLabel tun = new JLabel("UserName"); 
    tun.setBounds(10,10,140,25); 
    c.add(sun); 

    JTextField tuname = new JTextField(10); 
    tuname.setToolTipText("Enter your StaffId "); 
    tuname.setBounds(145,10,200,25); 
    c.add(tuname); 

    JLabel tpw = new JLabel("PassWord"); 
    tpw.setBounds(10,50,140,25); 
    c.add(tpw); 

    JPasswordField tpword = new JPasswordField(10); 
    tpword.setEchoChar('*'); 
    tpword.setBounds(145,50,200,25); 
    c.add(tpword); 
} 
} 

被引用在編譯時這我得到這種類型的錯誤的任何人都可以找我有什麼不對這個代碼，因爲我可以在actionlistrener段

Studentlogin.java:9: error: non-static method getContentPane() cannot be referen 
ced from a static context 
       Container c = getContentPane(); 
          ^
Studentlogin.java:11: error: non-static method setTitle(String) cannot be refere 
nced from a static context 
       setTitle(" Staff Signin "); 
       ^
Studentlogin.java:12: error: non-static method setSize(int,int) cannot be refere 
nced from a static context 
       setSize(400 , 300); 
       ^

Answer 1

你需要從靜態到去非靜態上下文中執行這個代碼相同類型的格式。最簡單的方法是創建你的類的實例，並調用一個方法，例如go。

public class Studentlogin extends JFrame{ 
    public static void main(String[] args) { 
     new Studentlogin().go(); 
    } 

    private void go() { 
     Container c = getContentPane(); 

     setTitle(" Staff Signin "); 
     setSize(400 , 300); 
     setLayout(new FlowLayout()); 
     setVisible(true); 
     setLayout(null); 

     JLabel tun = new JLabel("UserName"); 
     tun.setBounds(10,10,140,25); 
     c.add(sun); 

     JTextField tuname = new JTextField(10); 
     tuname.setToolTipText("Enter your StaffId "); 
     tuname.setBounds(145,10,200,25); 
     c.add(tuname); 

     JLabel tpw = new JLabel("PassWord"); 
     tpw.setBounds(10,50,140,25); 
     c.add(tpw); 

     JPasswordField tpword = new JPasswordField(10); 
     tpword.setEchoChar('*'); 
     tpword.setBounds(145,50,200,25); 
     c.add(tpword); 
    } 

}