中心的JPanel -java

Question

內部垂直的JButton我有4個小組，北，南，東，西邊界佈局。例如在東邊，我有一個jpanel，它有四個按鈕。我的問題是，所有按鈕都對齊到頂部，我想對齊中心。在CSS例如邊緣頂部或頂部的例子：50％。

任何想法？

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"); 

Answer 1

您需要更改contentor3的佈局。嘗試是這樣的：類似

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);