java JOptionPane错误找不到showMessageDialog（<null>，String，int）的合适方法
代码如下：
class ButtonHearerer implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
///////////////
if ( event.getSource() == overviewButton )
{
welcomeJPanel.setVisible(false);
overviewJPanel.setVisible(true);
get.add ( overviewJPanel );
}
/////////////////
else
if ( event.getSource() == infoButton )
{
JOptionPane.showMessageDialog(null,
"<html>"
+ "<tr><th>ID INFORMATION</th><tr><table style ='border:2px solid black'>"
+ "<tr><td halign='left'>Programmer</td><td align=center width = 200px>:</td><td align=right>Mohamed Ahmed</td></tr>"
+ "<tr><td halign='left'>Assignment #</td><td align=center width = 200px>:</td><td align=right>Final Project</td></tr>"
+ "<tr><td halign='left'>Assignment Name</td><td align=center width = 200px>:</td><td align=right>The Final Escape</td></tr>"
+ "<tr><td halign='left'>Course # and Title</td><td align=center width = 200px>:</td><td align=right>CISC 190 - Java</td></tr>"
+ "<tr><td halign='left'>Instructor</td><td align=center width = 200px>:</td><td align=right>Professor Forman</td></tr>"
+ "<tr><td halign='left'>Hours</td><td align=center width = 200px>:</td><td align=right>MW 9:35 - 12:45</td></tr>"
+ "<tr><td halign='left'>Difficulty</td><td align=center width = 200px>:</td><td align=right>9</td></tr>"
+ "<tr><td halign='left'>Completion Date</td><td align=center width = 200px>:</td><td align=right>05/21/14</td></tr>"
+ "<tr><td halign='left'>Program Name</td><td align=center width = 200px>:</td><td align=right>MohamedsFinalRevised</td></tr></table>"
+"</html>",
"ID Info",
JOptionPane.PLAIN_MESSAGE);
}
//////////////
else
if ( event.getSource() == acctBalButton )
{
String playersDeposit = deposit.getText();
doubleDeposit = Double.parseDouble(playersDeposit);
String acctBalText = accountBalance(acctBalTxt);
acctBalance = doubleDeposit - totalFee;
String playersAlias = alias.getText();
JOptionPane.showMessageDialog(null,"Account Balance", "<html>THE GREATEST ESCAPE ACCOUNT BALANCE\n"
+ "===================================="
+ "\n\n Summary of" + name + "Account for"
+ "alias of" + playersAlias + ":"
+ "\n"+ moneyFormatter.format(playersDeposit)
+ " in the THE GREATEST ESCAPE GAME IN THE WORLD"
+ "- Total ESCAPE Registration Fee\n"
+ moneyFormatter.format(totalFee)
+ "- Total Escape Registration Fee\n"
+ "=====\n"
+ moneyFormatter.format(acctBalance)
+ "- Current Account Balance\n\n"
+ "HAVE A NICE DAY...</html>",
JOptionPane.PLAIN_MESSAGE);
}
因此，我刚刚更新了代码并运行了它，但是当我按下按钮时，我收到了以下错误：
Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: Cannot format given Object as a Number
at java.text.DecimalFormat.format(DecimalFormat.java:507)
at java.text.Format.format(Format.java:157)
at MohamedsFinalRevised.accountBalance(MohamedsFinalRevised.java:1252)
at MohamedsFinalRevised$ButtonHearerer.actionPerformed(MohamedsFinalRevised.java:1338)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2346)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6525)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6290)
at java.awt.Container.processEvent(Container.java:2234)
at java.awt.Component.dispatchEventImpl(Component.java:4881)
at java.awt.Container.dispatchEventImpl(Container.java:2292)
at java.awt.Component.dispatchEvent(Component.java:4703)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4898)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4533)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4462)
at java.awt.Container.dispatchEventImpl(Container.java:2278)
at java.awt.Window.dispatchEventImpl(Window.java:2739)
at java.awt.Component.dispatchEvent(Component.java:4703)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:746)
at java.awt.EventQueue.access$400(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:697)
at java.awt.EventQueue$3.run(EventQueue.java:691)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:86)
at java.awt.EventQueue$4.run(EventQueue.java:719)
at java.awt.EventQueue$4.run(EventQueue.java:717)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:716)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
# 1 楼答案
JOptionPane需要组件、标题、消息、图标）如果我在代码中看到的正确，您只需给它3个参数
看一看
试试这个：
# 2 楼答案
对第一个参数使用new JFrame（）而不是null