java - 从 ArrayList 中删除对象以及 Jlist 中相应的索引

Question

我有一个类，它读取对象文件并将其导入到 ArrayList 中。然后我制作了一个 Jlist 来显示该 ArrayList 中每个对象的一些信息。因此，当他们选择 Jlist 中的一个元素时，它将显示 ArrayList 中相应的整个索引对象。我想添加一个“删除”按钮来从 ArrayList 中删除选定的 Jlist 元素和相应的索引对象。然后更新 Jlist，显示该元素已被删除。

这是我的课:

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.Font;
import java.io.File;
import java.io.FileInputStream;
import java.io.ObjectInputStream;
import java.util.ArrayList;

import javax.swing.DefaultListModel;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.ListModel;
import javax.swing.ListSelectionModel;
import javax.swing.SwingConstants;
import javax.swing.border.EmptyBorder;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import javax.swing.JScrollPane;
import javax.swing.JList;

import java.awt.TextArea;

import javax.swing.JTable;
import javax.swing.JTextPane;
import javax.swing.JTextArea;
import javax.swing.JComboBox;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JTextField;
import javax.swing.JButton;

import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;


public class LogBook2 extends JFrame {


    private static ArrayList<Log> logList = new ArrayList<Log>();



    private static String logs;



    private JPanel contentPane;
    private JScrollPane scrollPane;
    private JList list;
    private JScrollPane scrollPane_1;
    private String tpContent;

    private int diveNumber;
    private int diveDate;
    private String diveMonth;
    private int diveYear;
    private String location;
    private String diveSite;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    LogBook frame = new LogBook();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public LogBook2() {


        //===============================================================================
        //Importing form the Object file to ArrayList "logList" 
        File fileOfLogs=new File("logList.txt");
        if(fileOfLogs.exists()){
            try{
                ObjectInputStream myStream = new ObjectInputStream(new FileInputStream("logList.txt"));

                logList = (ArrayList<Log>) myStream.readObject();



                myStream.close();


            }
            catch(Exception e){
                setVisible(false);
                JOptionPane.showMessageDialog(null, " 00000 There was a problem while reading dive records.\n "
                        + "Please contact SEASFiRE Tech Team.", "Error", JOptionPane.ERROR_MESSAGE);

            }

        }
        else if(!fileOfLogs.exists()){
            JOptionPane.showMessageDialog(null, " 11111 There was a problem while reading dive records.\n "
                    + "Please contact SEASFiRE Tech Team.", "Error", JOptionPane.ERROR_MESSAGE);

        }
        //===============================================================================

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 888, 680);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);



        JScrollPane scrollPane_2 = new JScrollPane();
        scrollPane_2.setBounds(10, 88, 297, 542);
        contentPane.add(scrollPane_2);

        JList list_1 = new JList();
        scrollPane_2.setViewportView(list_1);
        list_1.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);


        //===============================================================================
        //getting some information of each object and making a Jlist element with it.
        DefaultListModel model=new DefaultListModel();
        for( int i=0;i<logList.size();i++){



            model.addElement(""+logList.get(i).getDiveNumber()+"__"+logList.get(i).getDiveDate()+"/"+logList.get(i).getDiveMonth()+"/"+logList.get(i).getDiveYear()
                    +"__"+logList.get(i).getLocation()+"_"+logList.get(i).getDiveSite());

        }

        list_1.setModel(model);


        //===============================================================================



        JLabel lblAddNewLog = new JLabel("Log Book");
        lblAddNewLog.setHorizontalAlignment(SwingConstants.CENTER);
        lblAddNewLog.setFont(new Font("Myanmar Text", Font.BOLD, 40));
        lblAddNewLog.setBounds(0, 16, 862, 61);
        contentPane.add(lblAddNewLog);



        scrollPane = new JScrollPane();
        scrollPane.setBounds(317, 88, 322, 542);
        contentPane.add(scrollPane);

        JTextArea textArea = new JTextArea();
        textArea.setEditable(false);
        scrollPane.setViewportView(textArea);
        JButton btnDelete = new JButton("Delete");
        //===============================================================================
        //trying to make the "Delete" button. Not working...
        btnDelete.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {


                model.remove(list_1.getSelectedIndex());
                list_1.remove(list_1.getSelectedIndex());
                textArea.setText("");
                list_1.clearSelection();






            }
        });
        btnDelete.setBounds(649, 561, 115, 29);
        contentPane.add(btnDelete);
        //========================================================================




        //========================================================================
        //the action for when an element is selected.
        list_1.addListSelectionListener(
                new ListSelectionListener(){
                    public void valueChanged(ListSelectionEvent event){
                        textArea.setText("");
                        textArea.append("Dive Number: "+logList.get(list_1.getSelectedIndex()).getDiveNumber()+"\t\tDive Date: "+
                    logList.get(list_1.getSelectedIndex()).getDiveDate()+"/"+logList.get(list_1.getSelectedIndex()).getDiveMonth()+
                    "/"+logList.get(list_1.getSelectedIndex()).getDiveYear()+"\n\nLocation: "+logList.get(list_1.getSelectedIndex()).getLocation()+
                    "\n\nDive Site: "+logList.get(list_1.getSelectedIndex()).getDiveSite()+"\n\nDive Type: "+logList.get(list_1.getSelectedIndex()).getDiveType()+
                    "\t\tCondition: "+logList.get(list_1.getSelectedIndex()).getCondition()+"\n\nVisibility: "+logList.get(list_1.getSelectedIndex()).getVisibility()+
                    "m\t\tSuit Type: "+logList.get(list_1.getSelectedIndex()).getSuitType()+"\n\nWeights: "+logList.get(list_1.getSelectedIndex()).getWeight()+
                    "m\t\tAltitude: "+logList.get(list_1.getSelectedIndex()).getAltitude()+"m\n\nTime In: "+logList.get(list_1.getSelectedIndex()).getHourIn()+
                    ":"+logList.get(list_1.getSelectedIndex()).getMinIn()+"\t\tDuration: "+logList.get(list_1.getSelectedIndex()).getDuration()+
                    "min\n\nMax Depth: "+logList.get(list_1.getSelectedIndex()).getMaxDepth()+"m\t\tSafety Stop: "+logList.get(list_1.getSelectedIndex()).getSafetyStop()+
                    "\n\nAir in: "+logList.get(list_1.getSelectedIndex()).getAirIn()+"bar\t\tAir Out: "+logList.get(list_1.getSelectedIndex()).getAirOut()+
                    "bar\n\n02 Perc: "+logList.get(list_1.getSelectedIndex()).getOxgPerc()+"%\t\tDive Buddy: "+logList.get(list_1.getSelectedIndex()).getDiveBuddy()+
                    "\n\nNote: "+logList.get(list_1.getSelectedIndex()).getNote());


                    }
                }
            );



        //========================================================================







    }
}

Answer 1

不要保留单独的 ArrayList 来保存数据。

相反，所有数据都应该存储在 ListModel 中

DefaultListModel<Log> model = new DefaultListModel<Log>();
model.addElement(...);
JList<Log> list = new JList<Log>( model );

然后，您为 JList 创建一个自定义呈现器，以显示您想要的 Log 类中的任何数据:

list.setCellRenderer( new DefaultListCellRenderer()
{
    public Component getListCellRendererComponent(
            JList list, Object value, int index, boolean isSelected, boolean cellHasFocus)
    {
        super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
        Log log = (Log)value;
        setText( log.get...() ):
        return this;
    }
});

现在您只有一个位置的数据，因此当您想要删除一行时，只需从 DefaultListModel 中删除该行即可。

如果您想了解如何从 ListModel 中删除条目，请查看 Swing 教程 How to Use Lists 中的部分。 。 “Fire”按钮将删除所选行。本教程还将详细解释如何使用自定义渲染器。