这是我年底项目的一小部分，我正在尝试在jframe中添加一条与jlabel的直线。如果我移除jlabel，那么该行将显示，否则它不会显示。我只知道JavaSwing，因此我对java图形没有任何经验。
提前感谢：）

import java.awt.EventQueue;
import java.awt.Graphics;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JLabel;

public class Draw extends JFrame {

    private JPanel contentPane;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    Draw frame = new Draw();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public Draw() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 569, 461);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);

        JLabel lbl = new JLabel("Show ");
        lbl.setBounds(263, 90, 49, 14);
        contentPane.add(lbl);
    }

    @Override
    public void paint(Graphics g) {
        g.drawLine(100, 100, 0, 0);
        g.drawArc(200, 200, 120, 100, 0, 180);
    }
}