testbutton.java

来自「这是一张java应用教程的随书光盘」· Java 代码 · 共 30 行

import java.applet.*;
import java.awt.*;
import java.awt.event.*;  
public class Testbutton extends Applet implements ActionListener
{ TextField text1,text2,text3;Label label1,label2;
  Button button1;
  public void init()
  { text1=new TextField(5);
    text2=new TextField(5);
    text3=new TextField(5);
    label1=new Label("+");
    label2=new Label("=");
    add(text1);add(label1);add(text2);add(label2); add(text3); 
    button1=new Button("确定");    
    add(button1); 
    button1.addActionListener(this); 
   }   
 
  public void actionPerformed(ActionEvent e)
  {  double n;
    if(e.getSource()==button1)
    { double n1,n2;  
      n1=Double.valueOf(text1.getText()).doubleValue();
      n2=Double.valueOf(text2.getText()).doubleValue();
      n=n1+n2;  
      text3.setText(String.valueOf(n));  
    }
    
  }  
}