hier eine sehr sehr billige Version
das ist meine erste Version gewesen

dient eher als Wegweiser...
machs auf jedenfall alleine sonst bringt es nichts
import java.awt.*;
import java.awt.event.*;
class taschenrechner extends Frame
{
TextField tf1;
TextField tf2;
TextField tf3;
Button bPlus;
Button bMinus;
Button bMal;
Button bTeilen;
public taschenrechner (String title)
{
this.setLayout(null);
this.setVisible(true);
this.setSize(800,600);
this.setTitle("Taschenrechner");
tf1=new TextField();
tf1.setBounds(150,80,200,25);
this.add(tf1);
tf2=new TextField();
tf2.setBounds(150,160,200,25);
this.add(tf2);
tf3=new TextField();
tf3.setBounds(150,240,200,25);
this.add(tf3);
bPlus = new Button();
bPlus.setLabel("+");
bPlus.setBounds(450,200,50,25);
bPlus.setFont(new Font("Arial", Font.PLAIN,10));
bPlus.setBackground(new Color(0xEEEFFF));
this.add(bPlus);
bPlus.addActionListener(new Aktion());
bMinus = new Button();
bMinus.setLabel("-");
bMinus.setBounds(450,250,50,25);
bMinus.setFont(new Font("Arial", Font.PLAIN,10));
bMinus.setBackground(new Color(0xEEEFFF));
this.add(bMinus);
bMinus.addActionListener(new Aktion());
bMal = new Button();
bMal.setLabel("*");
bMal.setBounds(550,200,50,25);
bMal.setFont(new Font("Arial", Font.PLAIN,10));
bMal.setBackground(new Color(0xEEEFFF));
this.add(bMal);
bMal.addActionListener(new Aktion());
bTeilen = new Button();
bTeilen.setLabel("/");
bTeilen.setBounds(550,250,50,25);
bTeilen.setFont(new Font("Arial", Font.PLAIN,10));
bTeilen.setBackground(new Color(0xEEEFFF));
this.add(bTeilen);
bTeilen.addActionListener(new Aktion());
}
//Filter
class Aktion implements ActionListener
{
public void actionPerformed(ActionEvent a)
{
Object object = a.getSource();
if (object==bPlus)
plus(a);
if (object==bMinus)
minus(a);
if (object==bMal)
mal(a);
if (object==bTeilen)
teilen(a);
}
}
//Plus Methode
void plus(ActionEvent ev)
{
String Stf1 = tf1.getText();
String Stf2 = tf2.getText();
Float f1 = new Float(Stf1);
Float f2 = new Float(Stf2);
float ff1 = f1.floatValue();
float ff2 = f2.floatValue();
float summe = (ff1+ff2);
tf3.setText(String.valueOf(summe));
}
//Minus Methode
void minus(ActionEvent ev)
{
String Stf1 = tf1.getText();
String Stf2 = tf2.getText();
Float f1 = new Float(Stf1);
Float f2 = new Float(Stf2);
float ff1 = f1.floatValue();
float ff2 = f2.floatValue();
float summe = (ff1-ff2);
tf3.setText(String.valueOf(summe));
}
//Mal Methode
void mal(ActionEvent ev)
{
String Stf1 = tf1.getText();
String Stf2 = tf2.getText();
Float f1 = new Float(Stf1);
Float f2 = new Float(Stf2);
float ff1 = f1.floatValue();
float ff2 = f2.floatValue();
float summe = (ff1*ff2);
tf3.setText(String.valueOf(summe));
}
//Teilen Methode
void teilen(ActionEvent ev)
{
String Stf1 = tf1.getText();
String Stf2 = tf2.getText();
Float f1 = new Float(Stf1);
Float f2 = new Float(Stf2);
float ff1 = f1.floatValue();
float ff2 = f2.floatValue();
float summe = (ff1/ff2);
tf3.setText(String.valueOf(summe));
//tf3.setText(String.valueOf(((new Float (tf1.getText())).floatValue())/((new Float (tf2.getText())).floatValue())));
}
public static void main (String args[])
{
taschenrechner a= new taschenrechner("taschenrechner");
}
}