我正在尝试弄清楚如何正确使用JList。我正在努力将列表的使用与我自己的类/数据模型结合起来。
我的目标是在单独的类中提取列表，并从多个操作（按钮事件/动作侦听器）更改列表中显示的数据。
例如：如果用户选择了兼容的CSV文件，则列表应显示该文件的内容。该文件本身包含一个简单的播放列表，其复合如下：艺术家;标题;文件路径
如果用户将另一首歌曲添加到播放列表，则该列表应“刷新”。我读过一些关于“FireContents ......”的内容，但我首先想知道如何正确使用这些列表。
我要添加源代码的相关部分。任何帮助＆amp;建议表示赞赏。
public class MusicTrack implements project.model.Track{
private String strArtist;
private String strTitle;
private String strFilepath;
public MusicTrack(String strArtist, String strTitle, String strFilepath){
this.strArtist = strArtist;
this.strTitle = strTitle;
this.strFilepath = strFilepath;
}
MusicPlayer：
public class MusicPlayer implements ActionListener{
private JFrame mainframe;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
MusicPlayer window = new MusicPlayer();
window.mainframe.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public MusicPlayer() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
mainframe = new JFrame();
mainframe.setTitle("MusicPlayer");
mainframe.setBounds(100, 100, 450, 300);
mainframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainframe.setLocationRelativeTo(null);
// menu & menuitems
JMenuBar menuBar = new JMenuBar();
mainframe.setJMenuBar(menuBar);
JMenu mnFile = new JMenu("Datei");
menuBar.add(mnFile);
JMenuItem mnItemLoadNewList = new JMenuItem("Neue Liste laden");
mnFile.add(mnItemLoadNewList);
JMenuItem mnItemLoadLIst = new JMenuItem("Liste laden & anhängen");
mnFile.add(mnItemLoadLIst);
JMenuItem mnItemSave = new JMenuItem("Speichern");
mnFile.add(mnItemSave);
JMenuItem mnItemNewEntry = new JMenuItem("Neuer Eintrag");
mnFile.add(mnItemNewEntry);
JMenu mnSort = new JMenu("Sortieren");
menuBar.add(mnSort);
JMenuItem mnItemArtist = new JMenuItem("nach Interpret");
mnSort.add(mnItemArtist);
JMenuItem mnItemTitle = new JMenuItem("nach Titel");
mnSort.add(mnItemTitle);
GridBagLayout gridBagLayout = new GridBagLayout();
gridBagLayout.columnWidths = new int[]{450, 0};
gridBagLayout.rowHeights = new int[]{227, 29, 0};
gridBagLayout.columnWeights = new double[]{1.0, Double.MIN_VALUE};
gridBagLayout.rowWeights = new double[]{1.0, 0.0, Double.MIN_VALUE};
mainframe.getContentPane().setLayout(gridBagLayout);
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.BOTH;
JPanel listPanel = new JPanel();
listPanel.setLayout(gridBagLayout);
mainframe.getContentPane().add(listPanel);
listPanel.setVisible(true);
// Buttons
JButton btnPlayAll = new JButton("Play All");
GridBagConstraints gbc_btnPlayAll = new GridBagConstraints();
gbc_btnPlayAll.anchor = GridBagConstraints.NORTH;
gbc_btnPlayAll.fill = GridBagConstraints.HORIZONTAL;
gbc_btnPlayAll.gridx = 0;
gbc_btnPlayAll.gridy = 1;
mainframe.getContentPane().add(btnPlayAll, gbc_btnPlayAll);
//Action- & Eventlistener, registering individual ActionListener per Button
mnItemLoadNewList.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
JFileChooser fChoose = new JFileChooser();
FileNameExtensionFilter fExt = new FileNameExtensionFilter("CSV", "csv");
fChoose.setFileFilter(fExt);
int returnVal = fChoose.showOpenDialog(null);
if(returnVal == JFileChooser.APPROVE_OPTION){
JList<Track> list = new JList<Track>();
ListModel<Track> listModel = new DefaultListModel<Track>();
list.setModel(listModel);
JScrollPane sPane = new JScrollPane(list);
sPane.add(listPanel);
}
};
});
// FIXME - Attach!
mnItemLoadLIst.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
JFileChooser fChoose = new JFileChooser();
FileNameExtensionFilter fExt = new FileNameExtensionFilter("CSV", "csv");
fChoose.setFileFilter(fExt);
int returnVal = fChoose.showOpenDialog(null);
if(returnVal == JFileChooser.APPROVE_OPTION){
}
};
});
// FIXME - Save!
mnItemSave.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
JFileChooser fChoose = new JFileChooser();
FileNameExtensionFilter fExt = new FileNameExtensionFilter("CSV", "csv");
fChoose.setFileFilter(fExt);
int returnVal = fChoose.showOpenDialog(null);
if(returnVal == JFileChooser.APPROVE_OPTION){
File selcdFile = new File(fChoose.getSelectedFile().toString());
PlayList myPL = new PlayList();
myPL.getTracks();
try {
myPL.save(selcdFile);
} catch (IOException e1) {
JOptionPane.showMessageDialog(mainframe, e1 + "\n\nBitte eine kompatible Datei wählen.", "MusicPlayer Error", JOptionPane.WARNING_MESSAGE);
}
}
};
});
mnItemNewEntry.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
NewEntry myNewEntry = new NewEntry(new JFrame(), "Neuer Eintrag");
myNewEntry.setSize(300, 240);
myNewEntry.setLocationRelativeTo(mainframe);
myNewEntry.setVisible(true);
};
});
Class NewEntry
// FIXME - btnChooseFile
btnChooseFile.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
JFileChooser fChoose = new JFileChooser();
FileNameExtensionFilter fExt = new FileNameExtensionFilter("MP3", "mp3"); // FIXME add wave etc.
fChoose.setFileFilter(fExt);
int returnVal = fChoose.showOpenDialog(null);
if(returnVal == JFileChooser.APPROVE_OPTION){
txtFilepath.setText(fChoose.getSelectedFile().getAbsolutePath());
}
};
});
PlayList（包含简单的方法，如保存，加载）
public class PlayList implements project.model.PlayList{
private List<Track> playList = new LinkedList<>();
private String strDelimiter = ";";
public void setPlayList(List<Track> playList) {
this.playList = playList;
}
JList的代码，仍然令我头疼。
ListModel<PlayList> theModel = new DefaultListModel<PlayList>();
JList<PlayList> myJList = new JList<PlayList>(theModel);
for(int i = 0; i < myPlayList.getTracks().size(); i++){
theModel.addElement(i);
}
JScrollPane myScrollPane = new JScrollPane(myJList);
mainframe.add(myScrollPane);
答案 0 :(得分：2)
您应该首先阅读JList的{{3}}，因为有很多要涵盖的内容。不过这是概述：
DefaultListModel。