Set size JPanel inside a JFrame

Question

I�m trying to set the size of a custom JPanel inside of a custom JFrame
my code looks like this
public class myFrame extends JFrame
    public myFrame()
     //This set the size of JFrame but i dont want this
        //setSize(300,600);
        //add panel to frame
        MyPanel panel = new myPanel();
        Container contentPane = getContentPane();
        contentPane.add(panel);
class MyPanel extends JPanel
     public MyPanel()
          setSize(300, 600); //This don�t work, why??
          validate();
}Why wont setSize(300, 600) work inside class myPanel ???

Answer 1

@Op
You need to read a tutorial on layout managers. It looks like you don't know how they work.
The panel should call setPreferredSize, and the frame should call pack just before you are displaying the frame.
Kaj