[英]Unable to get each item from selected multiple line Jlist?
經過大量研究后,我仍然無法從選定的多行jlist中獲取項目。 這是我的listSelectionListener代碼:
list.addListSelectionListener(new ListSelectionListener() {
public void valueChanged(ListSelectionEvent e) {
ListModel model = list.getModel();
for(int i=0; i < model.getSize(); i++){
System.out.println( model.getElementAt(i));
}
}
});
我還添加了一個按鈕來打印所選項目:
btnNewButton.addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent e) {
ListModel model = list.getModel();
for(int i=0; i < model.getSize(); i++){
System.out.println( model.getElementAt(i));
}
}
});
但仍然得到相同的輸出:
com.example.main.Student@c36b5fb
com.example.main.Student@2e61eb2
com.example.main.Student@151f708e
com.example.main.Student@563e55b0
我期望輸出“名稱:Paul0年齡:0。” 我也嘗試添加DefaultlistModel而不是ListModel,但是輸出是相同的。 請幫助我讓每個項目都在所選行中。我正在使用JDK8。 以下是完整的工作代碼。
import java.awt.Component;
import javax.swing.DefaultListCellRenderer;
import javax.swing.DefaultListModel;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.ListModel;
import javax.swing.SwingUtilities;
import javax.swing.JButton;
import java.awt.BorderLayout;
import javax.swing.event.ListSelectionListener;
import javax.swing.event.ListSelectionEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
public class Test3 {
JList<Student> list;
DefaultListModel model;
public Test3() {
list = new JList();
list.addListSelectionListener(new ListSelectionListener() {
public void valueChanged(ListSelectionEvent e) {
ListModel model = list.getModel();
for(int i=0; i < model.getSize(); i++){
System.out.println( model.getElementAt(i));
}
}
});
model = new DefaultListModel();
for (int i = 0; i < 10; i++) {
model.addElement(new Student("Paul" + i, i));
}
list.setModel(model);
list.setCellRenderer(new MyListCellRenderer());
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(list);
JButton btnNewButton = new JButton("Print");
btnNewButton.addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent e) {
ListModel model = list.getModel();
for(int i=0; i < model.getSize(); i++){
System.out.println( model.getElementAt(i));
}
}
});
frame.getContentPane().add(btnNewButton, BorderLayout.NORTH);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new Test3();
}
});
}
private class MyListCellRenderer extends DefaultListCellRenderer {
@Override
public Component getListCellRendererComponent(
JList list, Object value, int index,
boolean isSelected, boolean cellHasFocus) {
super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
Student label = (Student) value;
String name = label.getName();
int age = label.getAge();
String labelText = "<html>Name: " + name + "<br/>Age: " + age;
setText(labelText);
return this;
}
}
}
class Student {
String name;
int age;
public Student(String name, int age) {
this.name = name;
this.age = age;
}
public String getName() { return name; }
public int getAge() { return age; }
}
getElementAt
返回指定位置的Object
,在您的情況下恰好是Student
。 System.out.println
正在使用對象的toString
方法來打印對象,因此,根據您的代碼,它似乎正在工作。
但是,如果要輸出"Name: Paul0 Age: 0."
,您需要更改Student
類並覆蓋toString
方法以滿足您的要求
class Student {
String name;
int age;
public Student(String name, int age) {
this.name = name;
this.age = age;
}
public String getName() { return name; }
public int getAge() { return age; }
public String toString() {
return "Name: " + getName() + " Age: " + getAge());
}
}
或類似的東西
您可能還想看看JList#getSelectedValuesList
以獲得用戶選擇的項目的List
(但我可能會打擾您的問題)
您還可以查看作為超類的對象 (請參見“ toString()方法”一節),以了解更多詳細信息。
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