OnlineHelp例子运行时异常：IllegalArgumentException
//-----------------------------
// 这是从书中拷贝下来的。编译时没错，运行时发现此异常。
// 请问错在哪？
//-----------------------------
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class OnlineHelp extends MIDlet implements CommandListener
{
private Display display;
private Command back;
private Command exit;
private Command help;
private Form form;
private TextBox helpMesg;
public OnlineHelp()
{
display = Display.getDisplay(this);
back = new Command("Back", Command.BACK, 2);
exit = new Command("Exit", Command.EXIT, 1);
help = new Command("Help", Command.HELP, 3);
form = new Form("Online Help Example");
helpMesg = new TextBox("Online Help", "Press Back to return to the previous screen or press Exit Exist to close this program.", 81, 0);
helpMesg.addCommand(back);
form.addCommand(exit);
form.addCommand(help);
form.setCommandListener(this);
helpMesg.setCommandListener(this);
}
public void startApp()
{
display.setCurrent(form);
}
public void pauseApp()
{
}
public void destroyApp(boolean unconditional)
{
}
public void commandAction(Command command,
Displayable displayable)
{
if (command == back)
{
display.setCurrent(form);
}
else if (command == exit)
{
destroyApp(false);
notifyDestroyed();
}
else if (command == help)
{
display.setCurrent(helpMesg);
}
}
}
------解决方法--------------------------------------------------------
刚才看了很久也没有发现问题
亲自在JB里运行了一下发现确是有IllegalArgumentException异常抛出
根据异常信息步入原来是这一句的问题
helpMesg = new TextBox("Online Help", "Press Back to return to the previous screen or press Exit Exist to close this program.", 81, 0);
