通過事件處理插入圖像？

Question

我遇到了java中事件處理的問題。

如果按下按鈕1，我想添加image1，如果按下按鈕2，我想要添加image2，等等。

這是我的代碼，直到現在;誰能幫忙？此代碼不能編譯。

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

public class MyPanel extends JPanel { 
    private JLabel jcomp1; 
    private JButton jcomp2; 
    private JButton jcomp3; 
    private JButton jcomp4; 
    private JButton jcomp5; 
    private JButton jcomp6; 
    private JButton jcomp7; 
    private JButton jcomp8; 
    private JButton jcomp9; 
    private ImageIcon image1; 
    private ImageIcon image2; 
    private ImageIcon image3; 
    private ImageIcon image4; 
    private ImageIcon image5; 
    private ImageIcon image6; 
    private ImageIcon image7; 
    private ImageIcon image8; 

    public MyPanel() { 
     //construct components 
     image1 = new ImageIcon(getClass().getResource("hang1.jpg")); 
     image2 = new ImageIcon(getClass().getResource("hang2.jpg")); 
     image3 = new ImageIcon(getClass().getResource("hang3.jpg")); 
     image4 = new ImageIcon(getClass().getResource("hang4.jpg")); 
     image5 = new ImageIcon(getClass().getResource("hang5.jpg")); 
     image6 = new ImageIcon(getClass().getResource("hang6.jpg")); 
     image7 = new ImageIcon(getClass().getResource("hang7.jpg")); 
     image8 = new ImageIcon(getClass().getResource("hang8.jpg")); 


     jcomp1 = new JLabel (image1); 
     jcomp2 = new JButton ("1"); 
     jcomp3 = new JButton ("2"); 
     jcomp4 = new JButton ("3"); 
     jcomp5 = new JButton ("4"); 
     jcomp6 = new JButton ("5"); 
     jcomp7 = new JButton ("6"); 
     jcomp8 = new JButton ("7"); 
     jcomp9 = new JButton ("8"); 

     //events 
     jcomp2.setActionCommand("1"); 
     jcomp3.setActionCommand("2"); 
     jcomp4.setActionCommand("3"); 
     jcomp5.setActionCommand("4"); 
     jcomp6.setActionCommand("5"); 
     jcomp7.setActionCommand("6"); 
     jcomp8.setActionCommand("7"); 
     jcomp9.setActionCommand("8"); 


     jcomp2.addActionListener(new ButtonClickListener()); 
     jcomp3.addActionListener(new ButtonClickListener()); 
     jcomp4.addActionListener(new ButtonClickListener()); 
     jcomp5.addActionListener(new ButtonClickListener()); 
     jcomp6.addActionListener(new ButtonClickListener()); 
     jcomp7.addActionListener(new ButtonClickListener()); 
     jcomp8.addActionListener(new ButtonClickListener()); 
     jcomp9.addActionListener(new ButtonClickListener()); 


     //adjust size and set layout 
     setPreferredSize(new Dimension(624, 537)); 
     setLayout(null); 

     //add components 

     add(jcomp2); 
     add(jcomp3); 
     add(jcomp4); 
     add(jcomp5); 
     add(jcomp6); 
     add(jcomp7); 
     add(jcomp8); 
     add(jcomp9); 

     // set component bounds (only needed by Absolute Positioning) 
     jcomp1.setBounds(15, 10, 595, 350); 
     jcomp2.setBounds(35, 375, 100, 25); 
     jcomp3.setBounds(190, 375, 100, 25); 
     jcomp4.setBounds(320, 375, 100, 25); 
     jcomp5.setBounds(465, 375, 100, 25); 
     jcomp6.setBounds(35, 450, 100, 25); 
     jcomp7.setBounds(190, 450, 100, 25); 
     jcomp8.setBounds(320, 450, 100, 25); 
     jcomp9.setBounds(465, 450, 100, 25); 
    } 

    class ButtonClickListener implements ActionListener{ 
     public void actionPerformed(ActionEvent e) { 
      String command = e.getActionCommand(); 
      if (command.equals("1")) { 
       jcomp1.set(image1); 
      } 

     }  
    } 


    public static void main (String[] args) { 
     JFrame frame = new JFrame("MyPanel"); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.getContentPane().add(new MyPanel()); 
     frame.pack(); 
     frame.setVisible (true); 
    } 
} 

Answer 1

設置按鈕或標籤的圖標。要做到這一點，你需要創建一個ImageIcon，它有多個從文件名或加載的圖像創建的構造函數。

jcomp1.setIcon(new ImageIcon(...));

Answer 2

我相信你試圖讓這樣的事情：

public class MyPanel extends JPanel { 

    private JLabel label; 
    private JButton[] buttons = new JButton[8]; 
    private ImageIcon[] images = new ImageIcon[8]; 

    public MyPanel() { 

     JPanel buttonPanel = new JPanel(new GridLayout(2, 4, 15, 10)); 

     for (int i = 0; i < images.length; i++) { 
      images[i] = new ImageIcon(getClass().getResource(i+1 + ".png")); 
      buttons[i] = new JButton(String.valueOf(i+1)); 
      buttons[i].setActionCommand(String.valueOf(i+1)); 
      buttons[i].addActionListener(new ButtonClickListener()); 
      buttonPanel.add(buttons[i]); 
     } 
     label = new JLabel(images[0]); 

     setLayout(new BorderLayout()); 
     add(label); 
     add(buttonPanel, BorderLayout.PAGE_END); 
    } 

    class ButtonClickListener implements ActionListener { 

     public void actionPerformed(ActionEvent e) { 

      label.setIcon(images[Integer.parseInt(e.getActionCommand()) - 1]); 
     } 
    } 

    public static void main(String[] args) { 

     JFrame frame = new JFrame("MyPanel"); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.getContentPane().add(new MyPanel()); 
     frame.pack(); 
     frame.setVisible(true); 
    } 
} 

注：

• 不要忘記改變圖像文件名。
• 你可以使用佈局管理器來獲得你想要的。
• 我刪除了setPreferredSize(new Dimension(624, 537));，因爲您沒有指定使這行無意義的調整行爲。 pack()會照顧你的尺寸。