GridBagLayout修復按重量x / y設置的空間

Question

我有一個框架，具有3個JPanels的以下布局。

----------------------------
|   |                      |
| l |                      |
| e |  //toppanel          |
| f |                      |   
| t |----------------------|
| p |                      |
| n |  //bottompanel       |
| l |                      |
|   |                      |
----------------------------

我通過使用GridBagLayout實現了這一點

這是該布局的代碼

public class UITests extends JFrame{
    public UITests(){
        setLayout(new GridBagLayout());

        //the three main panels
        JPanel leftPanel = new JPanel();
        JPanel topPanel = new JPanel();
        JPanel bottomPanel = new JPanel();

        leftPanel.setBackground(Color.YELLOW);
        topPanel.setBackground(Color.GREEN);
        bottomPanel.setBackground(Color.PINK);

        //position the three main panels
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 0;
        gbc.gridheight = 2;
        gbc.gridwidth = 1;
        gbc.fill = gbc.BOTH;
        gbc.weightx = .2;
        gbc.weighty = 1;
        getContentPane().add(leftPanel, gbc);

        gbc = new GridBagConstraints();
        gbc.gridx = 1;
        gbc.gridy = 0;
        gbc.gridheight = 1;
        gbc.gridwidth = 1;
        gbc.fill = gbc.BOTH;
        gbc.weightx = .8;
        gbc.weighty = .5;
        getContentPane().add(topPanel, gbc);

        gbc = new GridBagConstraints();
        gbc.gridx = 1;
        gbc.gridy = 1;
        gbc.gridheight = 1;
        gbc.gridwidth = 1;
        gbc.fill = gbc.BOTH;
        gbc.weightx = .8;
        gbc.weighty = .5;
        getContentPane().add(bottomPanel, gbc);


        setSize(600,600);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }
    public static void main(String[] args){
        new UITests();
    }
}

問題是，當我在頂部面板中添加JTable時，底部面板的高度會縮小，就像頂部面板的一些高度一樣。 以下是頂部面板中表格的代碼，在設置三個主面板的背景后添加。

Object[][] contents = {{"haha","hehe", "hihi", "hoho", "huhu"},
        {"haha","hehe", "hihi", "hoho", "huhu"},
        {"haha","hehe", "hihi", "hoho", "huhu"},
        {"haha","hehe", "hihi", "hoho", "huhu"}};
Object[] heads = {"Haha Head", "Hehe Head", "Hihi Head", "Hoho Head", "Huhu Head"};
JTable table = new JTable(contents, heads);
JScrollPane scrollTable = new JScrollPane(table);

//add components to topPanel
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.gridheight = 1;
gbc.gridwidth = 1;
gbc.weightx = 1;
gbc.weighty = 1;
gbc.fill = gbc.BOTH;
topPanel.setLayout(new GridBagLayout());
topPanel.add(scrollTable, gbc);

框架現在看起來像

----------------------------
|   |                      |
| l |                      |
| e |  //toppanel          |
| f |  //new table created |   
| t |                      |
| p |                      |
| n |                      |
| l |----------------------|
|   |  //bottompanel       |
----------------------------

那么，我怎樣才能使'weightx'或'weighty'創建的空間固定？

Answer 1

weightx/weighty用於分配額外的空間。 因此實際上容器會詢問兒童的首選尺寸，如果它比可用的小，則根據重量分配額外的像素。

因此，您可以定義保存JTable的JScrollPane首選大小