临时

 1 class Demo07GridBagLayout {
 2     void makeButton(String s, JFrame frame, GridBagLayout gbLayout, GridBagConstraints gbConstraints) {
 3         JButton button = new JButton(s);
 4         gbLayout.setConstraints(button, gbConstraints);
 5         frame.add(button);
 6     }
 7     public void run() {
 8         JFrame frame = new JFrame("第七个GUI程序 -> 拨号盘");
 9         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
10         frame.setBounds(200, 300, 300, 160);
11         GridBagLayout gbLayout = new GridBagLayout();                   // 创建GirdBagLayout布局管理器
12         GridBagConstraints gbConstraints = new GridBagConstraints();
13         frame.setLayout(gbLayout);                                      // 使用GirdBagLayout布局管理器
14         gbConstraints.fill = GridBagConstraints.BOTH;                   // 组件填充显示区域
15         gbConstraints.weightx = 0.0;                                    // 恢复默认值
16         gbConstraints.gridwidth = GridBagConstraints.REMAINDER;          // 结束行
17         JTextField textField = new JTextField("13612345678");
18         gbLayout.setConstraints(textField, gbConstraints);
19         frame.add(textField);
20         gbConstraints.weightx = 0.5;                                    // 指定分配区域
21         gbConstraints.weighty = 0.2;
22         gbConstraints.gridwidth = 1;
23         makeButton("7", frame, gbLayout, gbConstraints);                // 调用方法，添加按钮
24         makeButton("8", frame, gbLayout, gbConstraints);
25         gbConstraints.gridwidth = GridBagConstraints.REMAINDER;         // 结束行
26         makeButton("9", frame, gbLayout, gbConstraints);
27         gbConstraints.gridwidth = 1;                                    // 重置gridwidth
28         makeButton("4", frame, gbLayout, gbConstraints);
29         makeButton("5", frame, gbLayout, gbConstraints);
30         gbConstraints.gridwidth = GridBagConstraints.REMAINDER;
31         makeButton("6", frame, gbLayout, gbConstraints);
32         gbConstraints.gridwidth = 1;
33         makeButton("1", frame, gbLayout, gbConstraints);
34         makeButton("2", frame, gbLayout, gbConstraints);
35         gbConstraints.gridwidth = GridBagConstraints.REMAINDER;
36         makeButton("3", frame, gbLayout, gbConstraints);
37         gbConstraints.gridwidth = 1;
38         makeButton("返回", frame, gbLayout, gbConstraints);
39         gbConstraints.gridwidth = GridBagConstraints.REMAINDER;
40         makeButton("拨号", frame, gbLayout, gbConstraints);
41         // gbConstraints.gridwidth = 1;
42         frame.setVisible(true);                                         // 设置窗格可见
43     }
44 }
45 
46 class E {
47     public static void main(String args[]) {
48         new Demo07GridBagLayout().run(); // 为什么第一列会比较宽
49     }
50 }