如何在JFrame中增加自定义JPanel的高度？

Question

I want to increase the height of a custom JPanel in a JFrame . I tried to use pa.setSize(700,200) but it does not change anything.

Here is the code:

JFrame f = new JFrame("Hello");
f.setResizable(true);
JPanel pa = new JPanel();
JButton btn = new JButton("Exit");

pa.setBackground(Color.red);
pa.setSize(700, 200);

f.setUndecorated(true);
f.getContentPane().add(pa, BorderLayout.NORTH);
f.setSize(new Dimension(700,700));
f.setLocation(500, 500);
f.setVisible(true);

Answer 1

它非常简单的解决方案，而不是pa.setsize（）更改为pa.setPreferredSize（new Dimension（width，60））;