import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class Test5 extends JFrame implements WindowListener,ActionListener{
JLabel jl1=new JLabel("本金");
JLabel jl2=new JLabel("利率");
JLabel jl3=new JLabel("存款年数");
JLabel jl4=new JLabel("每年年金额总计");
JTextField jt1=new JTextField(10);
JTextField jt2=new JTextField(10);
JTextField jt3=new JTextField(10);
JTextArea ja1=new JTextArea(4,6);
JButton jbtnAdd=new JButton("计算");
//GridBagLayout gb;
;
/** Creates a new instance of Test5 */
public Test5(String s) {
super("s");
//GridBagLayout gd=new GridBagLayout();
Container jfrm=getContentPane();
//jfrm.setLayout(new GridLayout());
JPanel p1=new JPanel();
p1.setLayout(new GridLayout(3,2));
JPanel p2=new JPanel();
p2.setLayout(new GridLayout(2,1));
p1.add(jl1);
p1.add(jt1);
p1.add(jl2);
p1.add(jt2);
p1.add(jl3);
p1.add(jt3);
jfrm.add(p1,BorderLayout.WEST);
p2.add(jl4);
p2.add(ja1);
jfrm.add(p2,BorderLayout.SOUTH);
jfrm.add(jbtnAdd,BorderLayout.EAST);
addWindowListener(this);
jbtnAdd.addActionListener(this);
}
public static void main(String[] args) {
Test5 t=new Test5("计算");
t.setSize(400,300);
t.setVisible(true);
}
public void windowOpened(WindowEvent e) {
}
public void windowClosing(WindowEvent e) {
System.exit(0);
}
public void windowClosed(WindowEvent e) {
}
public void windowIconified(WindowEvent e) {
}
public void windowDeiconified(WindowEvent e) {
}
public void windowActivated(WindowEvent e) {
}
public void windowDeactivated(WindowEvent e) {
}
public void actionPerformed(ActionEvent e) {
double sum=1,nu1,nu2,nu3;
nu1=(double)Integer.parseInt(jt1.getText());
nu2=(double)Integer.parseInt(jt2.getText());
nu3=(double)Integer.parseInt(jt3.getText());
sum=sum*nu1*(1.0f+nu2);
for(int i=1;i<Integer.parseInt(jt3.getText());i++)
sum=sum*(1.0f+nu2);
ja1.setText(String.valueOf(sum));
//getWrapStyleWord() 获取换行方式（如果文本区要换行）。
}
}
对的