将项添加到另一个类的现有jlist中 [英] Adding items to an already existing jlist from another class

问题描述

我有一个使用NetBeans IDE中的Desing模式创建的jList（名为JList1），我想使用一个辅助类将项添加到该列表中，该类解析一个大的xml列表并从中获取数据。我的问题是，我真的不明白如何做到这一点，我已经尝试了很多不同的代码，尝试了一个模型，但不能正确。我是java（也是编程）的新手，我不明白我是否做过像
String [] ar = {one，two，three };

JList Jlist1 = new JList（ar）;

这创建了一个新的jList而不是使用我已创建的jList，不是吗？

I have a jList (named JList1) created using the Desing mode from NetBeans IDE, and I want to add items to that list using a secondary class which parses a big xml list and gets the data from it. My problem is that I dont really understand how to do this, I already tried a lot of different codes, tried with a model too, but cant get it right. I am new to java (and programming too), and I dont understand if I do something like
String[] ar = {"one", "two", "three"};
JList Jlist1 = new JList(ar);
this created a new jList instead of using my already created one, no ?

推荐答案

created using the Desing mode from NetBeans IDE,

• • maybe not good idea to be prisonier of code generated by

    将新项目添加到DefaultListModel

    add a new Item to DefaultListModel

    
    

    并且我想使用辅助类向该列表添加项目，
    解析一个大的xml列表并从中获取数据。

    and I want to add items to that list using a secondary class which parses a big xml list and gets the data from it.

    
    
    

    
    

    • 听起来像你有一个 Swing中的Concure ，必须在EDT上对已经可见的Swing GUI进行更新

      • sounds like as you have an issue with Concurency in Swing, updates to the already visible Swing GUI must be done on EDT

        使用 SwingWorker＃publish（）用于长期和艰苦的工作（解析一个大的xml列表并从中获取数据。）

        use SwingWorker#publish() for long and hard job (which parses a big xml list and gets the data from it.)

        例如，向DefaultListModel添加一个新项目

        for example, add a new Item to DefaultListModel

        import javax.swing.*;
        import java.awt.*;
        import java.awt.event.*;
        
        public class Testing extends JFrame {
        
            private static final long serialVersionUID = 1L;
            private DefaultListModel listModel = new DefaultListModel();
            private JList list = new JList(listModel);
            private int currentSelectedRow = 0;
            private int xX = 0;
        
            public Testing() {
                setLocation(400, 300);
                setDefaultCloseOperation(EXIT_ON_CLOSE);
                for (int x = 0; x < 9; x++) {
                    listModel.addElement("" + x);
                    xX++;
                }
                JScrollPane sp = new JScrollPane(list);
                add(sp, BorderLayout.CENTER);
                JButton btn1 = new JButton("Reset Model CastingModel");
                add(btn1, BorderLayout.NORTH);
                btn1.addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent ae) {
                        list.clearSelection();
                        DefaultListModel model = (DefaultListModel) list.getModel();
                        model.removeAllElements(); 
                        // note Swing GUI by default to freeze if is removed more that 
                        // 999 elemets from the JList or its underlaying XxxListModel, 
                        // to use repeatly Actions from SwingTimer on short period
                        for (int x = 0; x < 9; x++) {
                            model.addElement("" + (x + xX));
                            xX++;
                        }
                        list.setModel(model);
                    }
                });
        
                JButton btn2 = new JButton("Reset Model directly from Model");
                add(btn2, BorderLayout.SOUTH);
                btn2.addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent ae) {
                        list.clearSelection();
                        listModel.removeAllElements();
                        for (int x = 0; x < 9; x++) {
                            listModel.addElement("" + (x + xX));
                            xX++;
                        }
                    }
                });
                pack();
            }
        
            public static void main(String[] args) {
                SwingUtilities.invokeLater(new Runnable() {
                    @Override
                    public void run() {
                        new Testing().setVisible(true);
                    }
                });
            }
        }
        

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