Java：Swing：Jlist

Question

当我向Jlist输入名称时，名称会输出到列表的下半部分，如何将名称设置到窗口顶部

package Gui;

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

import javax.swing.*;

public class GUI implements ActionListener {

    JButton button;
    JTextField field;
    JList list;
    JTextField name1;
    DefaultListModel listModel;
    String name;

    public GUI(){
        listModel = new DefaultListModel();
        listModel.addElement(null);
        listModel.setSize(1);

        JFrame frame = new JFrame();
        JPanel panel = new JPanel();
        field = new JTextField("Enter Name", 10);
        button = new JButton("Click");
        list = new JList(listModel);        

        list.setBorder(BorderFactory.createEmptyBorder(120, 20, 20, 120));


        JScrollPane listScrollPane = new JScrollPane(list);

        panel.add(listScrollPane);
        listScrollPane.setWheelScrollingEnabled(true);

        panel.add(button);
        panel.add(field);

        frame.getContentPane().add(panel);
        frame.pack();
        frame.setVisible(true);

        button.addActionListener(this);

        }


    public void actionPerformed(ActionEvent arg0) {
        if(arg0.getSource() == button)
            name = field.getText();
        listModel.addElement(name);
    }
}

Answer 1

您只需使用add(0, object)方法。

而不是listModel.addElement(name)，listModel.add(0, name)会在列表顶部添加名称。

对于JList的大小，您不应使用此边框，而是为JSCrollPane选择preferredSize：

package Gui;
...    
import java.awt.Dimension;

public class GUI implements ActionListener {

    ...    
    public GUI(){
        ...
        list = new JList(listModel);

        JScrollPane listScrollPane = new JScrollPane(list);
        listScrollPane.setPreferredSize(new Dimension(100, 240));

        panel.add(listScrollPane);
        ...
    }

    public void actionPerformed(ActionEvent arg0) {
        if(arg0.getSource() == button)
            name = field.getText();
        listModel.add(0, name);
    }
}

---

资源：

• JavaDoc - DefaultListModel.add(int, Object)