import javax.swing.*;
import java.awt.*;
public class NULLLayoutDemo extends JFrame {
  private JLabel lbUser = new JLabel();
  private JLabel lbPassword = new JLabel();
  private JTextField tfUser = new JTextField();
  private JTextField tfPassword = new JTextField();
  private JButton btnLog = new JButton();
  private Container contrainer =getContentPane();
  public NULLLayoutDemo()  {
    super("空布局");
    this.setSize(350,200);
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE );
  }
  public static void main(String[] args) {
    NULLLayoutDemo frame = new NULLLayoutDemo();
    frame.setLayout();
    frame.show();
  }
  public void setLayout( )  {
    contrainer.setLayout(null);
    lbUser.setText("用戶名");
    contrainer.add(lbUser);
    lbUser.setBounds(16, 26, 42, 16);
    lbPassword.setText("密碼");
    contrainer.add(lbPassword);
    lbPassword.setBounds(16, 56, 40, 16);
    contrainer.add(tfUser);
    tfUser.setBounds(73, 25, 255, 22);
    contrainer.add(tfPassword);
    tfPassword.setBounds(73, 57, 253, 22);
    btnLog.setText("登錄");
    contrainer.add(btnLog);
    btnLog.setBounds(125, 101, 73, 25);
  }
}