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//W6.java
import java.awt.*;
import java.awt.event.*;
public class WW extends Frame implements ActionListener{
TextField f;
Button btn1,btn2;
MenuBar mb=new MenuBar();
Menu m1=new Menu("Yeah");
Menu m2=new Menu("doing");
Menu m3=new Menu("No");
MenuItem item=new MenuItem("something",new MenuShortcut(p));
CheckboxMenuItem checkbox=new CheckboxMenuItem("different");
MenuItem star=new MenuItem("Ask for more!");
W6(){
super("idea");
setSize(350,200);
add(f);
mb.add(m1);
checkbox.setState(true);
m1.add(m2);
m1.add(item);
m1.add(checkbox);
m1.addSeparator();
m1.add(star);
m2.add("China");
m2.add("daily");
mb.add(m3);
btn1=new Button("smile");
btn2=new Button("charming");
add(btn1);
add(btn2);
item.addActionListener(this);
star.addActionListener(this);
btn1.addActionListener(this);
btn2.addActionListener(this);
setMenuBar(mb);
show();
}
public void actionPerformed(ActionEvent e){
if(e.getSource()==star)
System.exit(0);
else if(e.getSource()==btn2)
System.exit(0);
else if(e.getSource()==btn1)
f.setText("你按下了"+e.getActionCommand());
else
f.setText(e.getActionCommand()+"被打开");
}
}
public class W6{
public static void main(String[] args){
}
}
import java.awt.*;
import java.awt.event.*;
class WW extends Frame implements ActionListener { //不应有public
TextField f = new TextField(); //没有生成实例
Button btn1, btn2;
MenuBar mb = new MenuBar();
Menu m1 = new Menu("Yeah");
Menu m2 = new Menu("doing");
Menu m3 = new Menu("No");
MenuItem item = new MenuItem("something", new MenuShortcut(p));
CheckboxMenuItem checkbox = new CheckboxMenuItem("different");
MenuItem star = new MenuItem("Ask for more!");
WW() { //构造函数为WW
super("idea");
setSize(350, 200);
add(f); //导致此行null异常
mb.add(m1);
checkbox.setState(true);
m1.add(m2);
m1.add(item);
m1.add(checkbox);
m1.addSeparator();
m1.add(star);
m2.add("China");
m2.add("daily");
mb.add(m3);
btn1 = new Button("smile");
btn2 = new Button("charming");
add(btn1);
add(btn2);
item.addActionListener(this);
star.addActionListener(this);
btn1.addActionListener(this);
btn2.addActionListener(this);
setMenuBar(mb);
show();
}
public void actionPerformed(ActionEvent e) {
if (e.getSource() == star)
System.exit(0);
else if (e.getSource() == btn2)
System.exit(0);
else if (e.getSource() == btn1)
f.setText("你按下了" + e.getActionCommand());
else
f.setText(e.getActionCommand() + "被打开");
}
}
public class W6 {
public static void main(String[] args) {
WW w = new WW();
}
}
import java.awt.*;
import java.awt.event.*;
public class W6 extends Frame implements ActionListener{
TextField f;
Button btn1,btn2;
MenuBar mb=new MenuBar();
Menu m1=new Menu("Yeah");
Menu m2=new Menu("doing");
Menu m3=new Menu("No");
MenuItem item=new MenuItem("something",new MenuShortcut(p));
CheckboxMenuItem checkbox=new CheckboxMenuItem("different");
MenuItem star=new MenuItem("Ask for more!");
W6(){
super("idea");
setSize(350,200);
f = new TextField();
add(f);
mb.add(m1);
checkbox.setState(true);
m1.add(m2);
m1.add(item);
m1.add(checkbox);
m1.addSeparator();
m1.add(star);
m2.add("China");
m2.add("daily");
mb.add(m3);
btn1=new Button("smile");
btn2=new Button("charming");
add(btn1);
add(btn2);
item.addActionListener(this);
star.addActionListener(this);
btn1.addActionListener(this);
btn2.addActionListener(this);
setMenuBar(mb);
show();
}
public void actionPerformed(ActionEvent e){
if(e.getSource()==star)
System.exit(0);
else if(e.getSource()==btn2)
System.exit(0);
else if(e.getSource()==btn1)
f.setText("你按下了"+e.getActionCommand());
else
f.setText(e.getActionCommand()+"被打开");
}
public static void main(String[] args){
Frame f = new W6();
f.show();
}
}
