java-简单计算器窗口

编程实现：有四个按钮，分别为加 减 乘 除；窗口中又三个文本行，单击任意一按钮，将两个文本行的数据进行相应运算，在第单个文本行中显示结果。

窗口如图所示 例：点击*出现计算结果；

package Chapter;import java.awt.*;
import java.awt.event.*;public class Scomputer extends  Frame{ public Scomputer(){
this.setSize(400,400);
this.setLayout(null);
this.setTitle("简单计算器");
this.setVisible(true);
this.setLayout(new FlowLayout(FlowLayout.LEFT,20,20));
Button sum=new Button("+");
Button sub=new Button("-");
Button mul=new Button("*");
Button divi=new Button("/");
TextField txt1=new  TextField();
TextField txt2=new  TextField();
TextField txt3=new  TextField();
txt3.setBounds(5, 5, 30, 20);
this.add(divi);
this.add(mul);
this.add(sub);
this.add(sum);
this.add(txt1);
this.add(txt2);
this.add(txt3);
this.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
System.exit(0);
}
});
sum.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){ 
int i=Integer.parseInt(txt1.getText());
int j=Integer.parseInt(txt2.getText());
txt3.setText(String.valueOf(i+j));
}
});
sub.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){ 
int i=Integer.parseInt(txt1.getText());
int j=Integer.parseInt(txt2.getText());
txt3.setText(String.valueOf(i-j));
}
});


mul.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){ 
int i=Integer.parseInt(txt1.getText());
int j=Integer.parseInt(txt2.getText());
txt3.setText(String.valueOf(i*j));
}
});
divi.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){ 
int i=Integer.parseInt(txt1.getText());
int j=Integer.parseInt(txt2.getText());
txt3.setText(String.valueOf(i/j));
}
});
}
public static void main(String[] args){
new Scomputer();
}
}