设置JPanel或JOptionPane的大小

Question

所以我想以某种方式设置我的JOptionPane的大小 - 没有设置它,它对我的​​目的来说太大了,看起来不会很好.这是我的代码:

   JScrollPane scrollpane = new JScrollPane(); 
   String categories[] = { "1. Problem One Problem One Problem One Problem One Problem One Problem One Problem One Problem One Problem One", "2. Problem Two", "3. Extended Family", "4. Extended Family", "5. Extended Family"};
   JList list = new JList(categories);
   errorListCellRenderer cellRenderer = new errorListCellRenderer();
   list.setCellRenderer(cellRenderer);
   scrollpane = new JScrollPane(list);
   JPanel panel = new JPanel(); 
   panel.add(scrollpane);
   JOptionPane.showMessageDialog(null, panel, "Error List",  
                                          JOptionPane.PLAIN_MESSAGE);

当我设置JPanel的大小时:

panel.setPreferredSize(new Dimension(500, 200));

滚动条消失,因此不会显示所有内容.

有任何想法吗？Java n00b ...

Answer 1

如果您只想更改JOptionPane窗口的大小,可以使用UIManager来完成.像这样:

UIManager.put("OptionPane.minimumSize",new Dimension(500,500)); 
JOptionPane.showMessageDialog(null, "Hi " );

Answer 2

请进行以下更改并查看；

1. 不要将JScrollPane放在另一个面板中。直接在showMessageDialog（）中传递JScrollPane。

2. 还可以使用scrollPane.getViewport（）。add（list）;

编辑：我只是尝试了以下，并且滚动条对我来说是可见的随着项目的增加。

 JScrollPane scrollpane = new JScrollPane(); 
       String categories[] = { "1. Problem One Problem One Problem One Problem One Problem One Problem One Problem One Problem One Problem One", "2. Problem Two", "3. Extended Family", "4. Extended Family", "5. Extended Family"
               ,"6. Extended Family","7. Extended Family","8. Extended Family","9. Extended Family"};
       JList list = new JList(categories);

       scrollpane = new JScrollPane(list);

       JPanel panel = new JPanel(); 
       panel.add(scrollpane);

       scrollpane.getViewport().add(list);
       JOptionPane.showMessageDialog(null, scrollpane, "Error List",  
                                              JOptionPane.PLAIN_MESSAGE);

屏幕截图；

Answer 3

给滚动窗格一个preferredSize，然后将其直接添加到optionPane

String categories[] = { "1. Problem One Problem One Problem One Problem One Problem One Problem One Problem One Problem One Problem One",
                       "2. Problem Two", "3. Extended Family", "4. Extended Family", "5. Extended Family"};
JList list = new JList(categories);
JScrollPane scrollpane = new JScrollPane(list);
scrollpane.setPreferredSize(new Dimension(300,125));//<-----any size you want
JOptionPane.showMessageDialog(null, scrollpane, "Error List",JOptionPane.PLAIN_MESSAGE);