GridBagLayout占多行效果注意

如果想要出现按钮2占两行的效果，必须按键3、按钮4同时存在且同时可见。

• 如果缺少按钮4，则按钮2不会占两行；
• 如果缺少按钮3、4，则按钮2也不会占两行。

---

 package com.wst.bj;

 import java.awt.GridBagConstraints;
 import java.awt.GridBagLayout;

 import javax.swing.JButton;
 import javax.swing.JFrame;

 class GridBagText {

     JFrame jframe = new JFrame("搜索");

     JButton jButton = new JButton("按钮1");
     JButton jButton2 = new JButton("按钮2");
     JButton jButton3 = new JButton("按钮3");
     JButton jButton4 = new JButton("按钮4");

     public GridBagText() {

         init();
     }

     private void init()
     {
         FrameUtil.initFram(jframe, 500, 700);

         GridBagLayout gridBagLayout = new GridBagLayout();
         jframe.setLayout(gridBagLayout);
         GridBagConstraints constraints = new  GridBagConstraints();

         constraints.fill = GridBagConstraints.BOTH;
         constraints.weightx = 1.0;
         constraints.weighty = 1.0;

         constraints.gridheight = 1;
         constraints.gridwidth = GridBagConstraints.REMAINDER;
         gridBagLayout.setConstraints(jButton, constraints);
         jframe.add(jButton);

         constraints.gridheight = 2;
         constraints.gridwidth = 1;
         gridBagLayout.setConstraints(jButton2, constraints);
         jframe.add(jButton2);

         constraints.gridheight = 1;
         constraints.gridwidth = GridBagConstraints.REMAINDER;
         gridBagLayout.setConstraints(jButton3, constraints);
         jframe.add(jButton3);
         gridBagLayout.setConstraints(jButton4, constraints);
         jframe.add(jButton4);

         jframe.setSize(jframe.getPreferredSize());
         jframe.setVisible(true);
 //        jframe.pack();
     }
 }

---

 package com.wst.bj;

 import java.awt.GridBagConstraints;
 import java.awt.GridBagLayout;

 import javax.swing.JButton;
 import javax.swing.JFrame;

 class GridBagText {

     JFrame jframe = new JFrame("搜索");

     JButton jButton = new JButton("按钮1");
     JButton jButton2 = new JButton("按钮2");
     JButton jButton3 = new JButton("按钮3");
 //    JButton jButton4 = new JButton("按钮4");

     public GridBagText() {

         init();
     }

     private void init()
     {
         FrameUtil.initFram(jframe, 500, 700);

         GridBagLayout gridBagLayout = new GridBagLayout();
         jframe.setLayout(gridBagLayout);
         GridBagConstraints constraints = new  GridBagConstraints();

         constraints.fill = GridBagConstraints.BOTH;
         constraints.weightx = 1.0;
         constraints.weighty = 1.0;

         constraints.gridheight = 1;
         constraints.gridwidth = GridBagConstraints.REMAINDER;
         gridBagLayout.setConstraints(jButton, constraints);
         jframe.add(jButton);

         constraints.gridheight = 2;
         constraints.gridwidth = 1;
         gridBagLayout.setConstraints(jButton2, constraints);
         jframe.add(jButton2);

         constraints.gridheight = 1;
         constraints.gridwidth = GridBagConstraints.REMAINDER;
         gridBagLayout.setConstraints(jButton3, constraints);
         jframe.add(jButton3);
 //        gridBagLayout.setConstraints(jButton4, constraints);
 //        jframe.add(jButton4);

         jframe.setSize(jframe.getPreferredSize());
         jframe.setVisible(true);
 //        jframe.pack();
     }
 }

---

 package com.wst.bj;

 import java.awt.GridBagConstraints;
 import java.awt.GridBagLayout;

 import javax.swing.JButton;
 import javax.swing.JFrame;

 class GridBagText {

     JFrame jframe = new JFrame("搜索");

     JButton jButton = new JButton("按钮1");
     JButton jButton2 = new JButton("按钮2");
 //    JButton jButton3 = new JButton("按钮3");
 //    JButton jButton4 = new JButton("按钮4");

     public GridBagText() {

         init();
     }

     private void init()
     {
         FrameUtil.initFram(jframe, 500, 700);

         GridBagLayout gridBagLayout = new GridBagLayout();
         jframe.setLayout(gridBagLayout);
         GridBagConstraints constraints = new  GridBagConstraints();

         constraints.fill = GridBagConstraints.BOTH;
         constraints.weightx = 1.0;
         constraints.weighty = 1.0;

         constraints.gridheight = 1;
         constraints.gridwidth = GridBagConstraints.REMAINDER;
         gridBagLayout.setConstraints(jButton, constraints);
         jframe.add(jButton);

         constraints.gridheight = 2;
         constraints.gridwidth = 1;
         gridBagLayout.setConstraints(jButton2, constraints);
         jframe.add(jButton2);

 //        constraints.gridheight = 2;
 //        constraints.gridwidth = GridBagConstraints.REMAINDER;
 //        gridBagLayout.setConstraints(jButton3, constraints);
 //        jframe.add(jButton3);
 //        gridBagLayout.setConstraints(jButton4, constraints);
 //        jframe.add(jButton4);

         jframe.setSize(jframe.getPreferredSize());
         jframe.setVisible(true);
 //        jframe.pack();
     }
 }