Question

我正在编写一个测试函数，在按钮点击时动态地将元素添加到JPanel。我正在使用GridBagLayout。这是我的功能代码：

 public void buildGui(){
       ConnectionInfoPanel.removeAll();
       //test first group of items
       listOfLabels.add(new JLabel("Label 1"));
       listOfLabels.add(new JLabel("Label 2"));
       listOfLabels.add(new JLabel("Label 3"));
       listOfLabels.add(new JLabel("Label 4"));

       GridBagConstraints c = new GridBagConstraints();
              c.weightx = 1;
              c.weighty = 1;
              c.insets = new Insets(10,10,10,10);
              c.anchor = GridBagConstraints.NORTHWEST;

        ConnectionInfoPanel.add(listOfLabels.get(0), c);
        ConnectionInfoPanel.add(new JLabel(), c);

        ConnectionInfoPanel.add(listOfLabels.get(1), c);
        ConnectionInfoPanel.add(new JLabel(), c);


        ConnectionInfoPanel.add(listOfLabels.get(2), c);
        ConnectionInfoPanel.add(new JLabel(), c);

        ConnectionInfoPanel.add(listOfLabels.get(3), c);
        ConnectionInfoPanel.add(new JLabel(), c);

       //test second group
       listOfLabels.add(new JLabel("Label 5"));
       listOfLabels.add(new JLabel("Label 6"));
       listOfLabels.add(new JLabel("Label 7"));
       listOfLabels.add(new JLabel("Label 8"));

       GridBagConstraints x = new GridBagConstraints();
              x.weightx = 1;
              x.weighty = 2;
              x.insets = new Insets(10,10,10,10);
             // x.anchor = GridBagConstraints.NORTHWEST;

        ConnectionInfoPanel.add(listOfLabels.get(4), x);
        ConnectionInfoPanel.add(new JLabel(), x);

        ConnectionInfoPanel.add(listOfLabels.get(5), x);
        ConnectionInfoPanel.add(new JLabel(), x);


        ConnectionInfoPanel.add(listOfLabels.get(6), x);
        ConnectionInfoPanel.add(new JLabel(), x);

        ConnectionInfoPanel.add(listOfLabels.get(7), x);
        ConnectionInfoPanel.add(new JLabel(), x);

        ConnectionInfoPanel.updateUI();
    }

在第一组元素中一切正常。它们从左上角（0,0）开始排列。

但是在第二组元素中，它们的起始位置成为面板的中心（在Y轴上）和Label4的末端（在X轴上）。但我想要实现的是将他们的起始位置设置为（0,1）。所以这个组直接显示在第一个组之下。谁能告诉我我做错了什么？

Answer 1

您需要在网格约束中设置 gridX 和 gridY 值，否则布局管理器不知道放置组件的位置。

而且我认为你还使用gridX和gridY来混淆 weightX 和 weightY 。这是两件不同的事情。

对于每个组件，重置如下约束：

GridBagConstraints c = new GridBagConstraints();

c.gridx = 0;
c.gridy = 0;


ConnectionInfoPanel.add(listOfLabels.get(0), c);
c.gridx++;
ConnectionInfoPanel.add(listOfLabels.get(1), c);
c.gridx++;
ConnectionInfoPanel.add(listOfLabels.get(2), c);
c.gridx++;
ConnectionInfoPanel.add(listOfLabels.get(3), c);

c.gridx = 0;
c.gridy = 1;


ConnectionInfoPanel.add(listOfLabels.get(4), c);
c.gridx++;
ConnectionInfoPanel.add(listOfLabels.get(5), c);
c.gridx++;
ConnectionInfoPanel.add(listOfLabels.get(6), c);
c.gridx++;
ConnectionInfoPanel.add(listOfLabels.get(7), c);

如果你不知道列表有多长，那么你需要添加一些循环来连续递增y。

或者你可以将两行添加到两个flowlaout面板，然后将其添加到gridbaglaout面板，如下所示：

JPanel panel1 = new JPanel();
panel1.add(listOfLabels.get(0));
panel1.add(listOfLabels.get(1));
panel1.add(listOfLabels.get(2));
panel1.add(listOfLabels.get(3));
ConnectionInfoPanel.add(panel1, c);


JPanel panel2 = new JPanel();
panel2.add(new JLabel("Label 5"));
panel2.add(new JLabel("Label 6"));
panel2.add(new JLabel("Label 7"));
panel2.add(new JLabel("Label 8"));

GridBagConstraints x = new GridBagConstraints();
x.weightx = 1;
x.weighty = 2;
x.insets = new Insets(10, 10, 10, 10);
// x.anchor = GridBagConstraints.NORTHWEST;

x.gridy = 0;
ConnectionInfoPanel.add(panel1, x);
x.gridy = 1;
ConnectionInfoPanel.add(panel2, x);

GridBagLayout错误地显示元素

1 个答案: