GUI 프로그램 사진이 드롭 다운 메뉴 동작으로 변경됨 java

Question

입력 한 갤런 당 마일을 계산하는 프로그램을 작성했습니다. 드롭 다운 메뉴를 사용하여 km로 전환 할 수도 있습니다. 사진을 전환 할 때마다 전환 할 수있는 드롭 다운 메뉴를 선택하면되도록 노력하고 있습니다. 그래서 마일을위한 다른 그림과 km를위한 다른 하나. 그것의 바보 같지만 임무의 요구 사항 중의 하나. 어떻게해야합니까? 여기에 내가 현재 갖고있는 것, 나는 단지 내가 가지고있는 두 가지 사이에서 그림을 바꾸기를 원한다.

import java.awt.Component; 
import java.awt.event.*; 
import java.awt.*; 
import javax.swing.*; 
import static javax.swing.GroupLayout.Alignment.*; 
import net.miginfocom.swing.MigLayout; 
import javax.imageio.ImageIO; 
import java.awt.image.BufferedImage; 
import java.io.File; 
import java.io.IOException; 

public class mpg_mig extends JFrame { 
    public mpg_mig() { 

    JLabel titleLabel = new JLabel("Fuel Calculator"); 
    titleLabel.setFont(new Font("Serif", Font.BOLD, 18)); 
    titleLabel.setForeground(Color.blue); 

    final JLabel distLabel = new JLabel("Miles:"); 
    final JTextField distText = new JTextField(10); 
    JLabel traveledLabel = new JLabel("traveled"); 

    final JLabel fuelLabel = new JLabel("Gas:"); 
    final JTextField fuelText = new JTextField(10); 

    final JLabel mpgLabel = new JLabel("Miles per gallon:"); 
    final JTextField mpgText = new JTextField(10);  

    JButton clearButton = new JButton("Clear"); 
    JButton calcButton = new JButton("Calculate"); 

    String[] actStrings = { "Miles", "kiloMeters" }; 
    JComboBox jComboBox1 = new JComboBox(actStrings); 
    jComboBox1.setEditable(true);  

    String sFileName = "circuit1.png"; 

     BufferedImage image = null; 
     try {     
     image = ImageIO.read(new File(sFileName)); 
    } catch (IOException ex) { 

     System.out.println (ex.toString()); 
     System.out.println(sFileName); 

     JOptionPane.showMessageDialog(null,ex.toString() + " " + sFileName); 

     System.exit(0); 

    } 

    JLabel labelPic1 = new JLabel(new ImageIcon(image)); 


    setResizable(false); 

    JPanel p = new JPanel(new MigLayout("", "[] [] []",  
             "[] [] [] [] []")); 

    p.setBackground(Color.WHITE); 
    setContentPane(p); 

    p.add(labelPic1, "cell 0 0 1 3"); //(column 0, row 0, width 1, height 3) 
    p.add(clearButton, "cell 0 3");  //(column 0, row 3) 
    p.add(calcButton, "cell 0 4");  //(column 0, row 4) 

    p.add(titleLabel, "cell 1 0"); //(column 1, row 0) 
    p.add(distLabel, "cell 1 1"); //(column 1, row 1) 
    p.add(fuelLabel, "cell 1 2"); //(column 1, row 2) 
    p.add(mpgLabel, "cell 1 3"); //(column 1, row 3)   
    p.add(jComboBox1, "cell 1 4"); //(column 1, row 4) 

    p.add(distText, "cell 2 1"); //(column 2, row 1) 
    p.add(fuelText, "cell 2 2"); //(column 2, row 2) 
    p.add(mpgText, "cell 2 3"); //(column 2, row 3) 

     clearButton.addActionListener(new ActionListener() 
     { public void actionPerformed(ActionEvent event) 
      { 
      distText.setText(""); 
      fuelText.setText(""); 
      mpgText.setText(""); 
      } 
     }); 

     calcButton.addActionListener(new ActionListener() 
     { public void actionPerformed(ActionEvent event) 
      { 

      if(isNumeric(distText.getText()) && 
       isNumeric(fuelText.getText())) 
      { 
       double fuel; 
       double dist; 
       double result; 

       fuel = Double.parseDouble(fuelText.getText()); 
       dist = Double.parseDouble(distText.getText()); 
       result = dist/fuel; 
       result = Round(result,2); 

       mpgText.setText(String.format("%f", result)); 
      } 
      else 
      { 
       JOptionPane.showMessageDialog(null, "Enter distance traveled and fuel used"); 
      } 
      }     

     }); 

     jComboBox1.addActionListener(new ActionListener() 
     { public void actionPerformed(ActionEvent event) 
      { 
      //JComboBox jComboBox1 = (JComboBox)event.getSource(); 
       JComboBox jComboBox1 = (JComboBox)event.getSource(); 


      if(jComboBox1.getSelectedItem() == "Miles") 
      { 
       distLabel.setText("Miles"); 
       mpgLabel.setText("Miles per gallon:"); 
      } 
       else 
      { 
       distLabel.setText("KiloMeters"); 
       mpgLabel.setText("KM per liter:"); 
      } 

      } 
     });  

     setTitle("MPG and KML"); 
     pack(); //pack disables setting frames size... 
      setLocationRelativeTo(null);//center frame and showMessageDialog 
     setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);  
    } 

    private static boolean isNumeric(String text) 
    { try 
     { Double.parseDouble(text); } 
     catch (Exception e) 
     { return false; } 
     return true; 
    } 

    public double Round(double val, int plc) 
    { 
     double pwr = Math.pow(10,plc); 
     val = val * pwr; //shift to the left 
     double tmp = (int) val;  

     if(((int)(val + .5)) == (int) val) 
     return (tmp/pwr); //don't round up 
     else 
     return((tmp + 1.0)/pwr); //round up 
    } 

    public static void main(String args[]) { 
     java.awt.EventQueue.invokeLater(new Runnable() { 
      public void run() { 
       try { 
        UIManager.setLookAndFeel(

         UIManager.getCrossPlatformLookAndFeelClassName()); 
       } catch (Exception ex) { 
        ex.printStackTrace(); 
       } 
       new mpg_mig().setVisible(true); 
      } 
     }); 
    } 
    } 

Answer 1

// in the action detection 
labelPic1.setIcon(new ImageIcon(newImage)); 

Answer 2

당신은 당신의 콤보 상자에 ItemListener를 첨부해야합니다. 변화에, 당신은 *

또한 대신

public class SwitchPicture { 

    public static final String[] IMAGES = new String[]{ 
     "path/to/your/first/image", 
     "path/to/your/second/image" 
    }; 

    public static void main(String[] args) { 
     new SwitchPicture(); 
    } 

    public SwitchPicture() { 
     EventQueue.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       try { 
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); 
       } catch (ClassNotFoundException ex) { 
       } catch (InstantiationException ex) { 
       } catch (IllegalAccessException ex) { 
       } catch (UnsupportedLookAndFeelException ex) { 
       } 

       JFrame frame = new JFrame(); 
       frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
       frame.setLayout(new BorderLayout()); 
       frame.add(new SwitcherPane()); 
       frame.pack(); 
       frame.setVisible(true); 
      } 
     }); 

    } 

    protected class SwitcherPane extends JPanel { 

     private BufferedImage[] images; 
     private JLabel lblBackground; 
     private JComboBox comboBox; 

     public SwitcherPane() { 

      try { 
       images = new BufferedImage[2]; 
       for (int index = 0; index < 2; index++) { 
        images[index] = ImageIO.read(new File(IMAGES[index])); 
       } 
      } catch (IOException ex) { 
       ex.printStackTrace();; 
      } 

      setLayout(new BorderLayout()); 
      lblBackground = new JLabel(); 
      lblBackground.setIcon(new ImageIcon(images[0])); 

      add(lblBackground); 

      comboBox = new JComboBox(); 
      comboBox.getSelectedItem() 
      // I did this because the images where so large 
      // you couldn't see the combo box :P 
      comboBox.setFont(comboBox.getFont().deriveFont(48f)); 
      DefaultComboBoxModel<String> model = new DefaultComboBoxModel<>(); 
      model.addElement("Happy"); 
      model.addElement("Happier"); 
      comboBox.setModel(model); 
      comboBox.setSelectedIndex(0); 

      lblBackground.setLayout(new GridBagLayout()); 
      lblBackground.add(comboBox); 

      comboBox.addItemListener(new ItemListener() { 

       @Override 
       public void itemStateChanged(ItemEvent e) { 
        lblBackground.setIcon(new ImageIcon(images[comboBox.getSelectedIndex()])); 
       } 
      }); 


     } 
    } 
}