java - jpanel -java内垂直居中的jbutton

我的边框布局有4个面板，分别是北，南，东和西。例如在东边，我有一个带有四个按钮的jpanel。我的问题是所有按钮都与顶部对齐，而我想与中心对齐。例如在css中，诸如margin top或top:50％之类的东西。

有任何想法吗？

    JPanel contentor3 = new JPanel();
  contentor.add(contentor3, BorderLayout.EAST);
  contentor3.setBackground(Color.green);
  contentor3.setPreferredSize(new Dimension(120, 750));

  contentor3.add(btn[1]);
  btn[1].setText("btn1");

最佳答案

您需要更改contentor3的布局。尝试类似的方法:

contentor3.setLayout (new GridBagLayout());

GridBagConstraints gbc = new GridBagConstraints ();

// next two lines will place the components top-to-bottom, rather than left-to-right
gbc.gridx = 0;
gbc.gridy = GridBagConstraints.RELATIVE;

// add as many buttons as you want in a column
contentor3.add (new JButton ("btn1"), gbc);

contentor.add (contentor3, BorderLayout.EAST);