Anonymní profil MucQa – Programujte.com

#4 liborb
Zatím se mi povedlo udělat tohle 

package javaapplication4;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.lang.Math.*;

public class Kalkulacka extends JFrame implements ActionListener
{
    public JButton JB;
    public JTextField JTF;
    public float cislo;
    public String retezec, znak;
    public Kalkulacka ()
    {

        this.setSize(280, 65);
        this.setTitle("Kalkulacka");
        this.setLocation(500,500);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setLayout(new FlowLayout(FlowLayout.LEFT,10,3));
        JTF = new JTextField ("",20);
        JB = new JButton("Zaokrouhli!");
        this.getContentPane().add (JTF);
        this.getContentPane().add (JB);

                this.setVisible(true);
           
       JB.addActionListener
        (
                new java.awt.event.ActionListener()
                {

                @Override
                public void actionPerformed(ActionEvent e)
                {
                    retezec = JTF.getText();
                    cislo = Float.parseFloat(retezec);
                    
                    Math.round(10.3);
                    System.out.println("cislo = " + Math.round(Math.E));

                    JTF.setText("");
                    JTF.requestFocusInWindow();
                }
                }
        );
               
    }
public static void main (String [] args)
{
    try
    {
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    }
    catch (Exception e)
    {
        e.printStackTrace();
    }
    Kalkulacka okno = new Kalkulacka () ;
}

    @Override
    public void actionPerformed(ActionEvent e) {
        throw new UnsupportedOperationException("Not supported yet.");
    }
}

a nevím jak dál.. někde tam budou i chyby