private Handler handler = newHandler() {
    public void handleMessage(Message msg) {
          // 处理消息
    super.handleMessage(msg);
    switch (msg.what) {
    case 1:
      button1.setText("点击安装");
      break;
    case 2:
      button1.setText("打开");
      break;
    }
    };
 }; 

Message msg = handler.obtainMessage();
msg.what = 1;
handler.sendMessage(msg);

runOnUiThread(new Runnable() {
  @Override
  public void run() {
    // 更新UI的操作
  }
});

myView.post(new Runnable() {          
  @Override
  public void run() {
    // 更新UI
    myView.setText(“更新UI”);
  }});

private Handler handler = new Handler();

handler.post(new Runnable() {           
  @Override
  public void run() {
    // 更新UI
   myView.setText(“更新UI”);
  }});

private class DownloadFilesTask extends AsyncTask<URL, Integer, Long> 
 //在这里声明了Params、Progress、Result参数的类型
 {
   //因为这里不需要使用onPreExecute回调方法，所以就没有加入该方法
   
   //后台线程的目的是更具URL下载数据
    protected Long doInBackground(URL... urls) {
      int count = urls.length;//urls是数组，不止一个下载链接
      long totalSize = 0;//下载的数据
     for (int i = 0; i < count; i++) {
       //Download是用于下载的一个类，和AsyncTask无关，大家可以忽略他的实现
       totalSize += Downloader.downloadFile(urls[i]);
       publishProgress((int) ((i / (float) count) * ));//更新下载的进度
       // Escape early if cancel() is called
       if (isCancelled()) break;
     }
     return totalSize;
   }
 
   //更新下载进度
   protected void onProgressUpdate(Integer... progress) {
     setProgressPercent(progress[0]);
   }
 
   //将下载的数据更新到UI线程
   protected void onPostExecute(Long result) {
     showDialog("Downloaded " + result + " bytes");
   }
 }