GUI Jlist ItemListener

Question

いくつかの要素でJListを作成しようとしています。ユーザーが要素を選択すると、別のJListがウィンドウに表示されます。次に、ユーザーが他のリストの要素を選択すると、テキスト領域がウィンドウに表示されます。ここで私はこれまでに作ったものです：

import java.awt.*; 
import javax.swing.*; 
import java.awt.event.*; 
import java.util.*; 
public class ProductsList extends JFrame implements ItemListener { 


private JLabel availableDev; 
private JComboBox avDevBox 
private JTextArea itemDetails; 
private JList Items; 
private JList devicesForSale; 
private JList imandSJList; 
private JList applJList; 
private JList gamJList; 

public ProductsList() { 

    String[] avDevicesListItems = {"Image and Sound", "Appliance", "Gaming"}; 
    ArrayList<imageAndSound> iasList = new ArrayList<imageAndSound>; 
    ArrayList<Appliance> applianceList = new ArrayList<Appliance>; 
    ArrayList<Gaming> gamingList = new ArrayList<Gaming>; 

    //construct components 
    availableDev = new JLabel ("Available Devices"); 
    avDevicesList = new JList (avDevicesListItems); 
    itemDetails = new JTextArea (5, 5); 
    avDevBox = new JComboBox (avDevicesListItems); 
    devicesForSale = new JList(devList); 
    imandSJList = new JList(iasList); 
    applJList = new JList(applianceList); 
    gamJList = new JList(gamingList); 

    avDevBox.addItemListener(this); 

    //adjust size and set layout 
    setPreferredSize (new Dimension (944, 574)); 
    setLayout (null); 

    //add components 
    add (availableDev); 
    add (avDevicesList); 
    add (itemDetails); 
    add (avDevBox); 
    add(devicesForSale); 

    //set component bounds 
    availableDev.setBounds (35, 0, 100, 25); 
    avDevBOx.setBounds (25, 30, 120, 25); 
    itemDetails.setBounds (245, 225, 265, 215); 

    public void itemStateChanged(ItemEvent event) { 
     int choice = avDevBox.getSelectedIndex(); 
     if (choice = 0) { 
      add(imandSJList); 
      imandSJList.addItemListener(this); 
     } 
     else if (choice = 1){ 
      add(applJList); 
      applJList.addItemListener(this); 
     } 
     else { 
      add(gamJList); 
      gamJList.addItemListener(this); 
     } 
    } 


public static void main (String[] args) { 
    JFrame frame = new JFrame ("Products List"); 
    frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE); 
    frame.getContentPane().add (new MyPanel()); 
    frame.pack(); 
    frame.setVisible (true); 
    TV tv1 = new TV("LCD","28","720p","HDMI/DVI","11235","AT142","2015","SONY",500,5); //Creates object of class TV 
    TV tv2 = new TV("LED","32","1080p","HDMI/DVI","15394","AT168","2016","SAMSUNG",1000,0); //Creates object of class TV 
    bluerayDVD dvd = new bluerayDVD("DVD","720p","DVD-RW","15642","TT172","2015","SONY",400,100); //Creates object of class bluerayDVD 
    bluerayDVD blueray = new bluerayDVD("blueray","1080p","BD-R","18412","TT100","2015","SONY",500,1000); //Creates object of class bluerayDVD 
    Camera cam1 = new Camera("DSLR","50","stable","x5","2","19785","TC137","2016","SONY",600,50); //Creates object of class Camera 
    Camera cam2 = new Camera("compact,","40","stable","x7","1","16783","TC108","2016","SONY",700,70); //Creates object of class Camera 
    Console c1 = new Console("PS4","RGEN","1080p","Dolby","1 TB","15641","TG142","2016","SONY",400,80); //Creates object of class Console 
    Console c2 = new Console("XBOX","RGEN2","1080p","Dolby Digital","2 TB","13424","TG123","2016","MICROSOFT",400,10); //Creates object of class Console 
    Refrigerator f1 = new Refrigerator("Single door","C++","5kg","2kg","28756","TF357","2016","BOSS",1500,10); //Creates object of class Refrigerator 
    Refrigerator f2 = new Refrigerator("Double door","C++","8kg","4kg","26756","TF382","2016","SIEMENS",500,5); //Creates object of class Refrigerator 
    WashMachines wM1 = new WashMachines("C++","2kg","200rs","49356","TW364","2016","SIEMENS",3000,10); //Creates object of class WashMachines 
    WashMachines wM2 = new WashMachines("C++","4kg","250rs","49579","TW376","2016","BOSS",5000,10); //Creates object of class WashMachines 
    imandSJList.add(tv1); 
    imandSJList.add(tv2); 
    imandSJList.add(dvd); 
    imandSJList.add(blueray); 
    imandSJList.add(cam1); 
    imandSJList.add(cam2); 
    gamJList.add(c1); 
    gamJList.add(c2); 
    applJList.add(f1); 
    applJList.add(f2); 
    applJList.add(wM1); 
    applJList.add(wM2); 
    } 
} 

すべてのボディは、より良い方法を提案する可能性があれば、私は
は同様にあなたは、各リストに直接リスナーを追加し続けることができますあなたに

Answer 1

をありがとう非常に喜んでいるだろう

import java.awt.Dimension; 
import java.awt.FlowLayout; 

import javax.swing.JFrame; 
import javax.swing.JLabel; 
import javax.swing.JList; 
import javax.swing.event.ListSelectionEvent; 
import javax.swing.event.ListSelectionListener; 

public class JListDemo extends JFrame { 

    public JListDemo() { 

     setSize(new Dimension(300, 300)); 
     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     setLayout(new FlowLayout()); 
     final JLabel label = new JLabel("Update"); 
     String[] data = { "one", "two", "three", "four" }; 
     final JList dataList = new JList(data); 

     dataList.addListSelectionListener(new ListSelectionListener() { 

      @Override 
      public void valueChanged(ListSelectionEvent arg0) { 
       if (!arg0.getValueIsAdjusting()) { 
        label.setText(dataList.getSelectedValue().toString()); 
       } 
      } 
     }); 
     add(dataList); 
     add(label); 

     setVisible(true); 

    } 

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

}