使用JPanel的JOptionPane

Question

我正在嘗試使用JPanel和JOptionPanel，以便我可以修改警報窗口的大小。我寫的代碼，因爲這：

JPanel panel = new JPanel(); 
//panel.setBackground(Color.RED); 
panel.setPreferredSize(new Dimension(500,500)); 

// display the jpanel in a joptionpane dialog, using showMessageDialog 
JFrame frame = new JFrame("JOptionPane showMessageDialog component example"); 

while (AlarmRS.next()) { 
    System.out.println(AlarmRS.getString("Description")); 
    //JOptionPane.showInternalMessageDialog(null, getPanel(), AlarmRS.getString("Description"), JOptionPane.INFORMATION_MESSAGE); 
    JOptionPane.showMessageDialog(frame,panel, AlarmRS.getString("Description"), JOptionPane.WARNING_MESSAGE); 
} 

然而，當我運行該程序，描述意味着在中間，而是，它進入標題欄。我怎樣才能使這項工作，使描述是警報窗口的主要文字？

Answer 1

的JavaDocs for showMessageDialog明確規定，第三放慢參數是對話框

的title（「爲對話框的標題字符串」）相反，創建一個JLabel其文本設置爲你想顯示什麼，添加它，它的panel

JPanel panel = new JPanel(new GridBagLayout()); 
//panel.setBackground(Color.RED); 
panel.setPreferredSize(new Dimension(500, 500)); 

while (AlarmRS.next()) { 
    System.out.println(AlarmRS.getString("Description")); 
    panel.add(new JLabel(AlarmRS.getString("Description"))); 
    //JOptionPane.showInternalMessageDialog(null, getPanel(), AlarmRS.getString("Description"), JOptionPane.INFORMATION_MESSAGE); 
    JOptionPane.showMessageDialog(frame, panel, "This is a title", JOptionPane.WARNING_MESSAGE); 
}