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【第18章：图形界面】_列表框：JList

发布时间：2021-01-18 15:53:29编辑：雪饮阅读（）

 列表框的实现

使用javax.swing.Jlist类可以实例化列表框
import javax.swing.JFrame ;
import javax.swing.JList ;
import java.util.Vector ;
import javax.swing.BorderFactory ;
import javax.swing.ListSelectionModel ;
import javax.swing.JScrollPane ;
import java.awt.Container ;
import java.awt.GridLayout ;
class MyList{
       private JFrame frame = new JFrame("Welcome To kasumi") ;
       private Container cont = frame.getContentPane() ;
       private JList list1 = null ;
       private JList list2 = null ;
 
       public MyList(){
              this.frame.setLayout(new GridLayout(1,3)) ;
              String nations[] = {"中国","巴西","美国","韩国","意大利","法国"} ;
              Vector<String> v = new Vector<String>() ;
              v.add("kasumi") ;
              v.add("snowDrink") ;
              v.add("ayane") ;
              this.list1 = new JList(nations) ;
              this.list2 = new JList(v) ;
 
              this.list1.setBorder(BorderFactory.createTitledBorder("你喜欢去那个国家旅游？")) ;
              this.list2.setBorder(BorderFactory.createTitledBorder("你最喜欢的角色？")) ;
 
              this.list1.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION) ;// 多选
              this.list2.setSelectionMode(ListSelectionModel.SINGLE_SELECTION) ;// 单选
 
              this.cont.add(new JScrollPane(this.list1)) ;
              this.cont.add(this.list2) ;
 
              this.frame.setSize(330,180) ;
              this.frame.setVisible(true) ;
       }
 
}
public class Hello{
       public static void main(String args[]) throws Exception{
              new MyList() ;
       }
};

关于选择模式：
使用 ListSelectionModel.SINGLE_SELECTION ，您只需选择一行即可。
使用 ListSelectionModel.SINGLE_INTERVAL_SELECTION ，您可以选择多个行，这些行位于一个块中，即只能选择连续行（用shift加鼠标左键） （例如，您可以选择第1行，但不能选择第1-3行和第4-6行）
使用ListSelectionModel.MULTIPLE_INTERVAL_SELECTION可以选择多个行并且这多个行可以不在同一个块，比如你可以选项第一行和第三行，即可以选择不连续行（用ctrl+鼠标左键）
用javax.swing.AbstractListModel类实现列表框
继承抽象类javax.swing.AbstractListModel并重写getElementAt与getSize方法也可以实现列表框
import javax.swing.JFrame ;
import javax.swing.JList ;
import javax.swing.BorderFactory ;
import javax.swing.ListSelectionModel ;
import javax.swing.JScrollPane ;
import javax.swing.AbstractListModel ;
import java.awt.Container ;
import java.awt.GridLayout ;
import java.awt.event.WindowAdapter ;
import java.awt.event.WindowEvent ;
class MyListModel extends AbstractListModel{
       private String nations[] = {"中国","巴西","美国","韩国","意大利","法国"} ;
       public Object getElementAt(int index){
              if(index<this.nations.length){
                     return this.nations[index] ;
              }else{
                     return null ;
              }
       }
       public int getSize(){
              return this.nations.length ;
       }
}
class MyList{
       private JFrame frame = new JFrame("Welcome To kasumi") ;
       private Container cont = frame.getContentPane() ;
       private JList list1 = new JList(new MyListModel()) ;
 
       public MyList(){
              this.frame.setLayout(new GridLayout(1,3)) ;
              this.list1.setBorder(BorderFactory.createTitledBorder("你喜欢去那个国家旅游？")) ;
 
              this.list1.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION) ;
 
              this.cont.add(new JScrollPane(this.list1)) ;
 
              this.frame.setSize(330,180) ;
              this.frame.setVisible(true) ;
       }
 
}
public class Hello{
       public static void main(String args[]) throws Exception{
              new MyList() ;
       }
};

列表框选择事件的监听
实现javax.swing.event.ListSelectionListener接口的valueChanged方法可以获取列表框中列表项的选择事件
import javax.swing.JFrame ;
import javax.swing.JList ;
 
import javax.swing.BorderFactory ;
import javax.swing.ListSelectionModel ;
import javax.swing.JScrollPane ;
import javax.swing.AbstractListModel ;
import java.awt.Container ;
import java.awt.GridLayout ;
import java.awt.event.WindowAdapter ;
import java.awt.event.WindowEvent ;
import javax.swing.event.ListSelectionListener ;
import javax.swing.event.ListSelectionEvent ;
class MyListModel extends AbstractListModel{
       private String nations[] = {"中国","巴西","美国","韩国","意大利","法国"} ;
       public Object getElementAt(int index){
              if(index<this.nations.length){
                     return this.nations[index] ;
              }else{
                     return null ;
              }
       }
       public int getSize(){
              return this.nations.length ;
       }
}
class MyList implements ListSelectionListener{
       private JFrame frame = new JFrame("Welcome To MLDN") ;
       private Container cont = frame.getContentPane() ;
       private JList list1 = null ;
 
       public MyList(){
              this.frame.setLayout(new GridLayout(1,3)) ;     
              String nations[] = {"中国","巴西","美国","韩国","意大利","法国"} ;
              this.list1 = new JList(new MyListModel()) ;
 
              this.list1.setBorder(BorderFactory.createTitledBorder("你喜欢去那个国家旅游？")) ;
 
              this.list1.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION) ;// 多选
 
              this.cont.add(new JScrollPane(this.list1)) ;
 
              this.frame.setSize(330,180) ;
              this.frame.setVisible(true) ;
              this.list1.addListSelectionListener(this) ;
       }
 
       public void valueChanged(ListSelectionEvent e){      // 事件处理
              int temp[] = list1.getSelectedIndices() ;
              System.out.print("选定的内容：") ;
              for(int i=0;i<temp.length;i++){
                     System.out.print(list1.getModel().getElementAt(i) + "、") ;
              }
              System.out.println() ;
       }
 
}
public class Hello{
       public static void main(String args[]) throws Exception{
              new MyList() ;
       }
};