没有面板你画不了的,你可以在jpanel上画,也可以在其它jcomponent上画,但这些都必须加在 jframe jwindow等上面 public class a extends JFrame { public void paint(Graphics g){ g.drawRect(1,2,3,4) } public static void main(String args[]) { a aa = new a(); a.setSize a.show }}
public TreeTest() { super("hello"); Container c = getContentPane(); p = new MyPanel(); p.setPreferredSize(new Dimension(100, 100)); c.add(p); pack(); setVisible(true); }
public static void main(String[] args) { new TreeTest(); }
} class MyPanel extends JPanel { public void paint(Graphics g) { g.drawRect(1, 1, 20, 20); } }
jframe jwindow等上面
public class a extends JFrame {
public void paint(Graphics g){
g.drawRect(1,2,3,4)
} public static void main(String args[])
{
a aa = new a();
a.setSize
a.show
}}
import java.awt.*;public class TreeTest extends JFrame {
private MyPanel p;
public TreeTest() {
super("hello");
Container c = getContentPane();
p = new MyPanel();
p.setPreferredSize(new Dimension(100, 100));
c.add(p);
pack();
setVisible(true);
}
public static void main(String[] args) {
new TreeTest();
}
} class MyPanel extends JPanel {
public void paint(Graphics g) {
g.drawRect(1, 1, 20, 20);
}
}