JTextFields和我的學校項目

Question

對於我的化學課，我的老師告訴我，我可以通過製作某種化學相關課程來獲得額外的學分。我認爲這是一個好主意，因爲畢竟我在計算機科學專業。這是我的代碼到目前爲止，但我不能讓它顯示我想要的字符串，即使我按Enter鍵。任何幫助都會很棒。謝謝！

import java.awt.Color; 
import java.awt.Font; 
import java.awt.Graphics; 
import java.awt.event.KeyEvent; 
import java.awt.event.KeyListener; 
import javax.swing.*; 

    public class window extends JPanel implements KeyListener { 

     private static final long serialVersionUID = 1L; 
     private JTextField textBox; 
     private String textInput; 

     public window() { 
     textInput = ""; 
     textBox = new JTextField("Enter symbol here:", 30); 
     this.add(textBox); 
    } 

    public void paint(Graphics g) { 
     super.paint(g); 
     g.setColor(Color.CYAN); 
     g.setFont(new Font("", Font.BOLD, 20)); 
     g.drawString("Enter element symbol in text box above.", 110, 50); 
     g.drawString(textInput, 100, 100); 
    } 

    public void keyPressed(KeyEvent e) { 
     int code = e.getKeyCode(); 
     if (code == KeyEvent.VK_ENTER) { 
      textInput = textBox.getText(); 
     } 
     repaint(); 
    } 

    public void keyReleased(KeyEvent e) { 

    } 

    public void keyTyped(KeyEvent e) { 

    } 
} 



import java.awt.Color; 
import javax.swing.JFrame; 

    public class elementRunner { 

     public static void main(String[] args) { 
      window panel = new window(); 
     JFrame frame = new JFrame("Element project ~ By: Harsh Patel"); 
     frame.setBounds(100, 100, 600, 600); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.setResizable(false); 
     panel.setBackground(Color.RED); 
     frame.setVisible(true); 
     frame.addKeyListener(panel); 
     frame.add(panel); 
    } 
} 

Answer 1

問題是你的聽衆設置爲JPanel，如果你把它設置爲它工作的JTextField。我附上下面的代碼，但是，也許JLabels會有所幫助。我的意思是，它更容易，更結構化等，但你將不得不學習佈局如何工作。無論如何，這是它對我來說如何：

ElementRunner.java（大寫元素）。

public class ElementRunner { 

    public static void main(String[] args) { 
     MyWindow panel = new MyWindow(); 
     panel.setBackground(Color.RED); 

     JFrame frame = new JFrame("Element project ~ By: Harsh Patel"); 
     frame.setBounds(100, 100, 600, 600); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.setResizable(false); 
     frame.add(panel); 
     frame.setVisible(true); 

    } 
} 

MyWindow.java（窗口是太普通了，這樣，我們知道這是你的，大寫的像元）

public class MyWindow extends JPanel implements KeyListener { 

    private static final long serialVersionUID = 1L; 
    private JTextField textBox; 
    private String textInput; 

    public MyWindow() { 
     textInput = ""; 
     textBox = new JTextField("Enter symbol here:", 30); 
     textBox.addKeyListener(this); // This line adds the listener to the TextField 
     this.add(textBox); 
    } 

    public void paint(Graphics g) { 
     super.paint(g); 
     g.setColor(Color.CYAN); 
     g.drawString("Enter element symbol in text box above.", 110, 50); 
     g.drawString(textInput, 100, 100); 
    } 

    public void keyPressed(KeyEvent e) { 
     int code = e.getKeyCode(); 
     if (code == KeyEvent.VK_ENTER) { 
      textInput = textBox.getText(); 
     } 
     repaint(); 
    } 

    public void keyReleased(KeyEvent e) { } 

    public void keyTyped(KeyEvent e) { } 
}