Question

java-怎么改变按钮大小

menujP=new JPanel(new GridLayout(3,3));
mjB1=new JButton("开始");
mjB2=new JButton("说明");
mjB3=new JButton("退出");

menujP.add(mjB1,"North");
menujP.add(mjB2,"Center");
menujP.add(mjB3,"South");

Answer 1

jButton.setBounds(0, 0, 85, 82);

追问

setBounds和setSize都试过了，问题是setLayout(null)不行

追答

Dimension preferredSize = new Dimension(400,400);//设置尺寸
jButton.setPreferredSize(preferredSize );

为什么要放null。