import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class WindowChoice extends JFrame implements ItemListener,ActionListener{
JComboBox choice;
JTextField text;
JTextArea area;
JButton add,del;
public WindowChoice(){
init();
setLocation(300,300);
setSize(800,600);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
void init(){
setLayout(new FlowLayout());
choice = new JComboBox();
text = new JTextField();
area = new JTextArea(10,10);
choice.addItem("音乐天地");
choice.addItem("网络游戏");
choice.addItem("单机游戏");
choice.addItem("聊天室");
add = new JButton("添加");
add = new JButton("删除");
add.addActionListener(this);
text.addActionListener(this);
del.addActionListener(this);
choice.addItemListener(this);
add(choice);
add(text);
add(add);
add(new JScrollPane(area));
}
public void itemStateChanged(ItemEvent e){
String name = choice.getSelectedItem().toString();
int index = choice.getSelectedIndex();
area.setText("\n",+index+":"+name);
}
public void actionPerformed(ActionEvent e){
if(e.getSource() == add || e.getSource() == text){
String name = text.getText();
if(name.length()>0){
choice.addItem(name);
choice.setSelectedItem(name);
area.append("\n列表添加："+name);
}
}
else if(e.getSource() == del){
area.append("\n列表删除："+choice.getSelectedItem());
choice.remove(choice.getSelectedIndex());
}
}
}
这里出了什么问题啊 为什么不能运行 啊
------解决方案--------------------
你代码里面有两处错误，还没写main函数，改成下面就可以了
- Java code
import java.awt.*;import java.awt.event.*;import javax.swing.*;public class WindowChoice extends JFrame implements ItemListener,ActionListener{ JComboBox choice; JTextField text; JTextArea area; JButton add,del; public WindowChoice(){ init(); setLocation(300,300); setSize(800,600); setVisible(true); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } void init(){ setLayout(new FlowLayout()); choice = new JComboBox(); text = new JTextField(); area = new JTextArea(10,10); choice.addItem("音乐天地"); choice.addItem("网络游戏"); choice.addItem("单机游戏"); choice.addItem("聊天室"); add = new JButton("添加"); del = new JButton("删除");//这里有修改过 add.addActionListener(this); text.addActionListener(this); del.addActionListener(this); choice.addItemListener(this); add(choice); add(text); add(add); add(new JScrollPane(area)); } public void itemStateChanged(ItemEvent e){ String name = choice.getSelectedItem().toString(); int index = choice.getSelectedIndex(); area.setText("\n"+index+":"+name); //这里修改过 } public void actionPerformed(ActionEvent e){ if(e.getSource() == add || e.getSource() == text){ String name = text.getText(); if(name.length()>0){ choice.addItem(name); choice.setSelectedItem(name); area.append("\n列表添加："+name); } } else if(e.getSource() == del){ area.append("\n列表删除："+choice.getSelectedItem()); choice.remove(choice.getSelectedIndex()); } } public static void main(String[] args) { new WindowChoice(); }}
------解决方案--------------------