在我的GUI中沒有出現在Jframes中的文本

Question

所以我一直在關閉這個程序，並在幾天內開始工作，它是一個基本的客戶端服務器聊天室。我試圖讓它在啓動客戶端時彈出的gui文本在portnumber，servername和textbox JTextFields中。昨天是這種情況，但我已經改變了一些東西，現在gui在文本字段中沒有文字。該代碼位於try catch塊開始處運行的displaysettings方法中。任何人都知道它爲什麼不起作用？

import java.net.*; 
import java.util.*; 
import java.io.*; 
import java.awt.event.*; 

import javax.swing.JButton; 
import javax.swing.JComponent; 
import javax.swing.JFrame; 
import javax.swing.JLabel; 
import javax.swing.JPanel; 
import javax.swing.JTextArea; 
import javax.swing.JTextField; 

public class clienttry2 extends JFrame implements ActionListener { 
    JPanel panel1 = new JPanel(); 
    JPanel panel2 = new JPanel(); 
    JPanel panel3 = new JPanel(); 
    JButton send = new JButton("Send"); 
    JButton connect = new JButton("Connect"); 
    JLabel server = new JLabel("Server"); 
    JLabel port = new JLabel("Port"); 
    JButton disconnect = new JButton("Disconnect"); 
    static JTextField servername = new JTextField(10); 
    static JTextField portnumber = new JTextField(10); 
    static JTextField textbox = new JTextField(40); 
    JTextArea chatbox = new JTextArea(20,45); 

    static Boolean isconnected = false; 
    static Boolean sending = false; 
    static Socket server1; 
    static ObjectInputStream in; 
    static ObjectOutputStream out; 

    public clienttry2(){ 
     setTitle("Chat Room"); 
     setLayout(new java.awt.FlowLayout()); 
     setSize(600,500); 
     panel1.add(chatbox); //has all the chats 
     panel2.add(textbox); //area to type new messages into 
     panel2.add(send); send.addActionListener(this);//send button 
     panel3.add(server); 
     panel3.add(servername); 
     panel3.add(port);  
     panel3.add(portnumber); 
     panel3.add(connect); connect.addActionListener(this); 
     panel3.add(disconnect); disconnect.addActionListener(this); disconnect.setEnabled(false); 
     add(panel1); 
     add(panel2); 
     add(panel3); 
    } 

    public static void main(String[] args)throws Exception { 
     Client display = new Client(); 
     display.setVisible(true); 

     try{ 
      displaysettings(); 
      connect(); 
      setup(); 
      String message; 
      message = (String) in.readObject(); 
      System.out.println(message); 
     } catch (UnknownHostException e1) { 
      e1.printStackTrace(); 
     } catch (IOException e1) { 
      e1.printStackTrace(); 
     } 
    } 

    private static void displaysettings() { 
     portnumber.setText("3333"); 
     servername.setText("localhost"); 
     textbox.setText("This is where you type your messages to send to others on the server!"); 
    } 

    private static void connect() throws UnknownHostException, IOException { 
     server1 = new Socket("localhost", 3333); 
    } 

    private static void setup() throws IOException { 
     out = new ObjectOutputStream(server1.getOutputStream()); 
     out.flush(); 
     in = new ObjectInputStream(server1.getInputStream()); 
    } 

    public void actionPerformed(ActionEvent e){ 
     if(e.getSource()==connect) 
     { 
      System.out.println("connected"); 
      isconnected = true; 
      connect.setEnabled(false); 
      disconnect.setEnabled(true); 
     } 

     if(e.getSource()==send) 
     { 
      System.out.println("sending chat"); 
      sending = true; 
     } 
     if(e.getSource()==disconnect) 
     { 
      try { 
       server1.close(); 
       out.close(); 
       isconnected = false; 
       connect.setEnabled(true); 
       disconnect.setEnabled(false); 

      } catch (IOException e1) { 
       e1.printStackTrace(); 
      } 
     } 
    } 

Answer 1

Swing組件不會更新，除非被告知。當您設置的文本，請致電：

textbox.repaint();

迫使GUI更新。