java applet（画出幸福的笑脸）

Question

我打算使用java画一个笑脸，到目前为止，这是我的代码：

import javax.swing.JApplet;
import java.awt.Graphics;
public class HappyFace extends Japplet
{
    public void paint(Graphics canvas)
    {
        super.paint(canvas);
        canvas.drawOval(100, 50, 200, 200);
        canvas.fillOval(155, 100, 10, 20);
        canvas.fillOval(230, 100, 10, 20);
        canvas.drawArc(150, 160, 100, 50, 180, 180);
    }
}

我遇到以下错误：

HappyFace.java:3: error: cannot find symbol
public class HappyFace extends japplet
                               ^
  symbol: class japplet
HappyFace.java:7: error: cannot find symbol
        super.paint(canvas);
        ^
  symbol:   variable super
  location: class HappyFace
2 errors

Answer 1

因为没有扩展名为Japplet的超类。就像import语句所说的一样，它必须是JApplet。您需要按如下所示进行类声明：public class HappyFace extends JApplet