java - GridBagLayout - 意外添加/和更改间距

Question

所以，当我添加面板时，我对面板之间的间距变化(包含 JTextAreas )有疑问，请参阅此 picture 。 :D

示例

第一次按下按钮时addTextArea()叫做。图中状态1 -> 状态2。问题是 panel_buttons 与新添加的 WorkDescription 不太接近(JTextArea)。当多次按下按钮时，它们之间的间距会发生变化。

按钮之前发生了很大的跳跃，但是； c.weighty = 0.1 - 0.3跳跃较小。

// The panel is placed in the center of a JFrame (BorderLayout)
public CONSTRUCTOR {

    JPanel panel = new JPanel(new GridBagLayout());
    GridBagConstraints c = new GridBagConstraints();
    // ...
    c.anchor = GridBagConstraints.NORTHWEST;
    c.gridx = 0;
    c.gridy = 0;
    c.weightx = 1;
    c.weighty = 1;
    c.gridwidth = 1;
    c.gridheight = 1;
    // this is how everything looks at (first pic) start.
    panel.add(panel_buttons, c);   // panel_buttons is at the right place
}

添加新WorkDescription的方法，即JTextArea :

public void addTextArea() {

    WorkDescription wd = new WorkDescription(); //WorkDescription extends JPanel

    panel.remove(panel_buttons); 
    c.weighty = 0.25;       // I've messed around with the weighty alot.
                            // 0.2-0.25 makes the panel_buttons do the least amout of 'down-jump'
    panel.add(wd, c);

    if(c.gridy < 3 ) {
        c.gridy ++;
        c.weighty = 1;

        panel.add(panel_buttons, c);
    }
    panel.revalidate();
    panel.repaint();
}

Answer 1

我发现的最好的解决方案是，

从 GridBagLayout 切换到 GridLayout。

private JPanel panel_Center = new JPanel(new GridLayout(5,1)); 

然后，当然，删除所有 GridBagConstraints

public void addTextArea() {

    WorkDescription wd = new WorkDescription();

    panel.remove(panel_buttons); 
    panel.add(wd);

    if(addedWorks < 4 ) {       

        addedWorks++;
        panel.add(panel_buttons);

    }

    panel.revalidate();
    panel.repaint();
}