📌  相关文章
📜  Java Swing-JList

📅  最后修改于: 2020-09-30 05:58:55             🧑  作者: Mango

Java JList

JList类的对象表示文本项的列表。可以设置文本项列表，以便用户可以选择一项或多项。它继承了JComponent类。

JList类声明

我们来看一下javax.swing.JList类的声明。

public class JList extends JComponent implements Scrollable, Accessible

常用的构造函数：

Constructor Description
JList() Creates a JList with an empty, read-only, model.
JList(ary[] listData) Creates a JList that displays the elements in the specified array.
JList(ListModel dataModel) Creates a JList that displays elements from the specified, non-null, model.

常用方法：

Methods Description
Void addListSelectionListener(ListSelectionListener listener) It is used to add a listener to the list, to be notified each time a change to the selection occurs.
int getSelectedIndex() It is used to return the smallest selected cell index.
ListModel getModel() It is used to return the data model that holds a list of items displayed by the JList component.
void setListData(Object[] listData) It is used to create a read-only ListModel from an array of objects.

Java JList示例

import javax.swing.*;
public class ListExample
{
 ListExample(){
    JFrame f= new JFrame();
    DefaultListModel l1 = new DefaultListModel<>();
      l1.addElement("Item1");
      l1.addElement("Item2");
      l1.addElement("Item3");
      l1.addElement("Item4");
      JList list = new JList<>(l1);
      list.setBounds(100,100, 75,75);
      f.add(list);
      f.setSize(400,400);
      f.setLayout(null);
      f.setVisible(true);
 }
public static void main(String args[])
    {
   new ListExample();
    }}

输出：

带有ActionListener的Java JList示例

import javax.swing.*;
import java.awt.event.*;
public class ListExample
{
 ListExample(){
    JFrame f= new JFrame();
    final JLabel label = new JLabel();        
    label.setSize(500,100);
    JButton b=new JButton("Show");
    b.setBounds(200,150,80,30);
    final DefaultListModel l1 = new DefaultListModel<>();
      l1.addElement("C");
      l1.addElement("C++");
      l1.addElement("Java");
      l1.addElement("PHP");
      final JList list1 = new JList<>(l1);
      list1.setBounds(100,100, 75,75);
      DefaultListModel l2 = new DefaultListModel<>();
      l2.addElement("Turbo C++");
      l2.addElement("Struts");
      l2.addElement("Spring");
      l2.addElement("YII");
      final JList list2 = new JList<>(l2);
      list2.setBounds(100,200, 75,75);
      f.add(list1); f.add(list2); f.add(b); f.add(label);
      f.setSize(450,450);
      f.setLayout(null);
      f.setVisible(true);
      b.addActionListener(new ActionListener() {
          public void actionPerformed(ActionEvent e) { 
             String data = "";
             if (list1.getSelectedIndex() != -1) {                     
                data = "Programming language Selected: " + list1.getSelectedValue(); 
                label.setText(data);
             }
             if(list2.getSelectedIndex() != -1){
                data += ", FrameWork Selected: ";
                for(Object frame :list2.getSelectedValues()){
                   data += frame + " ";
                }
             }
             label.setText(data);
          }
       }); 
 }
public static void main(String args[])
    {
   new ListExample();
    }}

输出：