import java.awt.*;
import java.awt.event.*;public class ItemEventDemo implements ItemListener,WindowListener {
Frame f = new Frame("ItemEvent Demo");
Label msg = new Label("你最想去工作的地方是:");
Label output = new Label();
List cityList = new List(3);
public ItemEventDemo()
{
cityList.add("北京");
cityList.add("上海");
cityList.add("深圳");
f.add(msg ,"North");
f.add(cityList,"Center");
f.add(output,"South");
f.setSize(300,200);
f.setVisible(true);
f.addWindowListener(this);
cityList.addItemListener(this);
//ItemListener 接口中只有一个方法itemStateChanged
public void itemStateChanged(ItemEvent e)?????????显示void 对于变量 itemStateChanged 是无效类型 {
//ItemEVent 的事件源为cityList ,则将被选中的项显示在output
if(e.getSource()== cityList)
{
output.setText("你选择的城市是:"+ cityList.getSelectedItem()+ ",该选项的编号是:"+ e.getItem());
}
}
public static void main(String [] args)
{
new ItemEventDemo();
}
}
public void itemStateChanged(ItemEvent e) {
// TODO Auto-generated method stub
}
public void windowActivated(WindowEvent arg0) {
// TODO Auto-generated method stub
}
public void windowClosed(WindowEvent arg0) {
// TODO Auto-generated method stub
}
public void windowClosing(WindowEvent arg0) {
System.exit(0);
// TODO Auto-generated method stub
}
public void windowDeactivated(WindowEvent arg0) {
// TODO Auto-generated method stub
}
public void windowDeiconified(WindowEvent arg0) {
// TODO Auto-generated method stub
}
public void windowIconified(WindowEvent arg0) {
// TODO Auto-generated method stub
}
public void windowOpened(WindowEvent arg0) {
// TODO Auto-generated method stub
}
}
谁可以帮我解决一下,太谢谢你了,我是Java 初级学习者,高手们就帮帮忙吧!!!
import java.awt.event.*;public class ItemEventDemo implements ItemListener,WindowListener {
Frame f = new Frame("ItemEvent Demo");
Label msg = new Label("你最想去工作的地方是:");
Label output = new Label();
List cityList = new List(3);
public ItemEventDemo()
{
cityList.add("北京");
cityList.add("上海");
cityList.add("深圳");
f.add(msg ,"North");
f.add(cityList,"Center");
f.add(output,"South");
f.setSize(300,200);
f.setVisible(true);
f.addWindowListener(this);
cityList.addItemListener(this);
//ItemListener 接口中只有一个方法itemStateChanged
public void itemStateChanged(ItemEvent e)?????????显示void 对于变量 itemStateChanged 是无效类型 {
//ItemEVent 的事件源为cityList ,则将被选中的项显示在output
if(e.getSource()== cityList)
{
output.setText("你选择的城市是:"+ cityList.getSelectedItem()+ ",该选项的编号是:"+ e.getItem());
}
}
public static void main(String [] args)
{
new ItemEventDemo();
}
}
public void itemStateChanged(ItemEvent e) {
// TODO Auto-generated method stub
}
public void windowActivated(WindowEvent arg0) {
// TODO Auto-generated method stub
}
public void windowClosed(WindowEvent arg0) {
// TODO Auto-generated method stub
}
public void windowClosing(WindowEvent arg0) {
System.exit(0);
// TODO Auto-generated method stub
}
public void windowDeactivated(WindowEvent arg0) {
// TODO Auto-generated method stub
}
public void windowDeiconified(WindowEvent arg0) {
// TODO Auto-generated method stub
}
public void windowIconified(WindowEvent arg0) {
// TODO Auto-generated method stub
}
public void windowOpened(WindowEvent arg0) {
// TODO Auto-generated method stub
}
}
谁可以帮我解决一下,太谢谢你了,我是Java 初级学习者,高手们就帮帮忙吧!!!
还存在方法的重复定义import java.awt.Frame;
import java.awt.Label;
import java.awt.List;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;public class ItemEventDemo implements ItemListener,WindowListener{
Frame f = new Frame("ItemEvent Demo");
Label msg = new Label("你最想去工作的地方是:");
Label output = new Label();
List cityList = new List(3);
public ItemEventDemo(){
cityList.add("北京");
cityList.add("上海");
cityList.add("深圳");
f.add(msg,"North");
f.add(cityList,"Center");
f.add(output,"South");
f.setSize(300,200);
f.setVisible(true);
f.addWindowListener(this);
cityList.addItemListener(this);
} // ItemListener 接口中只有一个方法itemStateChanged
// 显示void 对于变量 itemStateChanged 是无效类型
public void itemStateChanged(ItemEvent e){
// ItemEVent 的事件源为cityList ,则将被选中的项显示在output
if(e.getSource() == cityList){
output.setText("你选择的城市是:" + cityList.getSelectedItem() + ",该选项的编号是:" + e.getItem());
}
} public static void main(String[] args){
new ItemEventDemo();
}
public void windowActivated(WindowEvent arg0){
// TODO Auto-generated method stub
}
public void windowClosed(WindowEvent arg0){
// TODO Auto-generated method stub
}
public void windowClosing(WindowEvent arg0){
System.exit(0);
// TODO Auto-generated method stub }
public void windowDeactivated(WindowEvent arg0){
// TODO Auto-generated method stub
public void windowDeiconified(WindowEvent arg0){
// TODO Auto-generated method stub }
public void windowIconified(WindowEvent arg0){
// TODO Auto-generated method stub }
public void windowOpened(WindowEvent arg0){
// TODO Auto-generated method stub }
}