超类不使用子类方法

Question

My Superclass is failing to use the method I created in my subclass. I get an error because I'm using the Graphics argument. What am I missing here?

I've tried the suggestions given by eclipse, however they result in more errors.

Here's my super class

  import java.awt.Canvas;
  import java.awt.Color;
  import java.awt.Graphics;
  import javax.swing.JFrame;
public class GameScreen extends Canvas{

public GameScreen() {

}

public static void main(String[] args) {
    // TODO Auto-generated method stub
//Sets Screen
    JFrame jframe = new JFrame("Game Screen");
    Canvas canvas = new GameScreen();
        jframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        canvas.setBackground(Color.cyan);
        canvas.setSize(1000,800);
        jframe.add(canvas);
        jframe.pack();
        jframe.setVisible(true);

        Paddle1.paint(Graphics g);

}



 }

And here's my subclass

    import java.awt.Color;
    import java.awt.Graphics;
public class Paddle1 extends GameScreen {

public void paint(Graphics g) {
    g.setColor(Color.white);
    g.fillRect(50, 50, 40, 130);
}
 }

The subclass creates a rectangle that is supposed to appear on top of the canvas

Answer 1

If you would like to trigger method "paint" of Paddle1, you have to modify your code as below:

JFrame jframe = new JFrame("Game Screen");
Canvas canvas = new Paddle1();
jframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
canvas.setBackground(Color.cyan);
canvas.setSize(1000,800);
jframe.add(canvas);
jframe.pack();
jframe.setVisible(true);
canvas.paint(g);