Gauge 有关问题请问_J2ME

Gauge 问题请教
各位前辈帮我看一下面的代码，Gauge 怎么增加不到指定的form 里的
下面的代码的意思是如果有form传进来就在指定的form上面显示一个进度条
我是在actionCommand 里调用这个类的。
是不是要刷新这个form还是怎么，这个Gauge一直没有显示出来。
但是如果我在调用Alert返回这个界面后这个Gauge是出来的。
请各位指教，谢谢！在经等待
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import javax.microedition.lcdui.*;
public class ThreadWait implements Runnable {
private int sec;
private Form form;
private String msg;
public ThreadWait(int sec,Form form,String msg){
this.sec=sec;
this.form=form;
this.msg=msg;
new Thread(this).run();
}
public void run(){
try{
if (form==null)
Thread.sleep(sec*1000);
else
{
Gauge gauge=new Gauge(msg,false,sec*1000,Gauge.CONTINUOUS_IDLE);
form.append(msg);
form.append(gauge);
for (int i=10*sec;i<=1000*sec;i+=10*sec)
{
Thread.sleep(10*sec);
gauge.setValue(i);
}

}
}
catch (Exception e)
{
System.out.println(e);
}
}
}

------解决方案--------------------------------------------------------
在你原思路上，修改了下ThreadWait类。

Java code

import javax.microedition.lcdui.*;public class ThreadWait implements Runnable {    private int sec;    private Form form;    private String msg;    public ThreadWait(int sec, Form form, String msg) {        this.sec = sec;        this.form = form;        this.msg = msg;        new Thread(this).start();    }    public void run() {        try {            if (form != null) {                Gauge gauge = new Gauge(msg, false, 100, Gauge.CONTINUOUS_IDLE);                form.append(msg);                int k = form.append(gauge);                while (gauge.getValue() != gauge.getMaxValue()) {                    gauge.setValue(gauge.getValue() + 1);                    Thread.sleep(10 * sec);                }                form.delete(k);            }        } catch (Exception e) {            System.out.println(e);        }    }}
------解决方案--------------------------------------------------------
package prj10_2;

import javax.microedition.lcdui.*

public class frm_MIDLet1 extends Form implements CommandListener,
		ItemStateListener, ItemCommandListener {
	private static frm_MIDLet1 frm;
	private TextField tf_id = new TextField("用户名", "", 20, TextField.ANY);
	private TextField tf_pw = new TextField("密  码", "", 20, TextField.NUMERIC
			| TextField.PASSWORD);
	private Command Cmd_login = new Command("登陆", Command.SCREEN, 1);
	private Command Cmd_del = new Command("删除", Command.BACK, 1);

	public frm_MIDLet1() {
		super("登陆界面");
		frm = this;
		this.append(tf_id);
		this.append(tf_pw);
		this.addCommand(Cmd_login);
		this.setCommandListener(this);
		this.setItemStateListener(this);
	}

	public void commandAction(Command c, Displayable d) {
		if (c == Cmd_login) {
				Gauge g = new Gauge("登陆验证", false, 100, 0);
				frm.append(g);
				thread_gauge tg = new thread_gauge(g);
				tg.start();
				try {
					tg.join();
				} catch (Exception ex) {
					ex.printStackTrace();
				}
				System.out.println("验证完毕");
		}
	}

	public void commandAction(Command c, Item i) {
		TextField tf = (TextField) i;
		int p = tf.getCaretPosition();