在子线程中更新ProgressBar为null

1   就是自己ProgressBar有两个，我在findViewbyId时填了另一个，所以tm的搞了半天才找到错误。

2 另外有个问题，先写在这，记得以前遇到过，忘了咋解决的了

这里在另一个子线程中修改pb_antivirus，这两个线程的步调可能不一致的啊，但是为啥能够正常执行？有大神解决吗

private void initUI() {
        iv_antivirus_bg=(ImageView)findViewById(R.id.iv_antivirus_bg);
        iv_antivirus_bg1=(ImageView)findViewById(R.id.iv_antivirus_bg1);
        tv_antivirus=(TextView)findViewById(R.id.tv_antivirus);
        pb_antivirus=(ProgressBar)findViewById(R.id.pb_antivirus);
        ll_layout=(LinearLayout)findViewById(R.id.ll_layout);
    }

private void initData() {
        
        new Thread(){
            public void run() {
                mAntivirusList=AntivirusDao.getAntivirus();  
                PackageManager pm=getPackageManager();
                List<PackageInfo> packageInfoList=pm.getInstalledPackages(
                        PackageManager.GET_SIGNATURES+PackageManager.GET_UNINSTALLED_PACKAGES);
                
                mAntivirusListT=new ArrayList<Antivirus>();

                pb_antivirus.setMax(packageInfoList.size());
                for(PackageInfo pif:packageInfoList){
                    
                    Antivirus antivirus=new Antivirus(); //病毒对象个体
                    Signature[] signatures=pif.signatures;
                    Signature signature=signatures[0];
                    String string=signature.toCharsString();
                    String md5=MD5Util.encoder(string);

                    for(Antivirus a:mAntivirusList){
                        if(a.getMd5().equals(md5)){
                            antivirus.setAntivirus(true);
                            antivirus.setDesc(a.getDesc());
                            mAntivirusListT.add(antivirus);
                        }else{
                            antivirus.setAntivirus(false);
                        }
                    }
                    
                    String name=pif.applicationInfo.loadLabel(pm).toString();
                    antivirus.setName(name);
                    
                    try {
                        Thread.sleep(50+new Random().nextInt(100)); 
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    
                    progress++;
                    pb_antivirus.setProgress(progress);
                    
                    Message msg=Message.obtain();
                    msg.obj=antivirus;
                    msg.what=SCANING;
                    mHandler.sendMessage(msg);
                }
                Message msg=Message.obtain();
                msg.what=SCAN_FINISH;
                mHandler.sendMessage(msg);
                
            };
            
        }.start();
        
    }