android - 使用 AsyncTask 更新我的进度条和状态栏中的文本

Question

我有一个下载 mp3 的异步任务，我在状态栏中有一个自定义的扩展通知，带有一个进度条和一个 TextView 。问题是我无法让他们更新。这是我的尝试，我做错了什么？

 public class DownloadFile extends AsyncTask<Void, Integer, String> {                       
    /*public WebRequest(Context context, 
            String ProgressTitle, String ProgressMessage) {
        this._context = context;

        this._title = ProgressTitle;
        this._message = ProgressMessage;
    }*/
    ProgressBar progressBar;
    private int progress = 0;
    NotificationManager notificationManager;
    Notification notification2;
    private static final int PROGRESS = 0x1;
    private static final int MAX_PROGRESS = 100;
    int downloadedSize;
    int totalSize;



    @Override
    protected void onPreExecute() {
        /*SDCardRoot = Environment.getExternalStorageDirectory() + "/download/";
        Intent in = new Intent(mainmenu.this, DownloadService.class);
        in.putExtra("url", SDCardRoot);
        in.putExtra("songname", filename3);
        startService(in);*/

        // get the layout
        //setContentView(R.layout.download_progress);

        // configure the intent
        Intent intent = new Intent();
        final PendingIntent pendingIntent = PendingIntent.getActivity(getApplicationContext(), 0, intent, 0);

        // configure the notification
        notification2 = new Notification(R.drawable.download, "DOWNLOADING: " + filename3, System
                .currentTimeMillis());
        notification2.flags = notification2.flags | Notification.FLAG_ONGOING_EVENT;
        notification2.contentView = new RemoteViews(getApplicationContext().getPackageName(), R.layout.download_progress);
        notification2.contentIntent = pendingIntent;
        notification2.contentView.setTextViewText(R.id.percentage,"hi" );
        notification2.contentView.setTextViewText(R.id.status_text, "DOWNLOADING: " + filename3);
        notification2.contentView.setProgressBar(R.id.status_progress, 100, progress, false);

        getApplicationContext();
        notificationManager = (NotificationManager) getApplicationContext().getSystemService(
                Context.NOTIFICATION_SERVICE);

        notificationManager.notify(2, notification2);


    }

    @Override
    protected String doInBackground(Void... params) {
        // TODO Auto-generated method stub

        try {

            //set the download URL, a url that points to a file on the internet
            //this is the file to be downloaded
            URL url = songURL2;


            //create the new connection
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();

            //set up some things on the connection
            urlConnection.setRequestMethod("GET");
            urlConnection.setDoOutput(true);

            //and connect!
            urlConnection.connect();

            //set the path where we want to save the file
            //in this case, going to save it on the root directory of the
            //sd card.
            SDCardRoot = Environment.getExternalStorageDirectory() + "/download/";
            //create a new file, specifying the path, and the filename
            //which we want to save the file as.
            File file = new File(SDCardRoot,filename3);

            //this will be used to write the downloaded data into the file we created
            FileOutputStream fileOutput = new FileOutputStream(file);

            //this will be used in reading the data from the internet
            InputStream inputStream = urlConnection.getInputStream();

            //this is the total size of the file
            Integer totalSize = urlConnection.getContentLength();
            //variable to store total downloaded bytes
            Integer downloadedSize = 0;

            //create a buffer...
            byte[] buffer = new byte[1024];
            int bufferLength = 0; //used to store a temporary size of the buffer

            //now, read through the input buffer and write the contents to the file
            while ( (bufferLength = inputStream.read(buffer)) > 0 ) {
                    //add the data in the buffer to the file in the file output stream (the     file on the sd card
                    fileOutput.write(buffer, 0, bufferLength);
                    //add up the size so we know how much is downloaded
                    downloadedSize += bufferLength;
                    //this is where you would do something to report the prgress, like this maybe
                    //updateProgress(downloadedSize, totalSize);
                    publishProgress(downloadedSize/totalSize);


            }
            //close the output stream when done
            fileOutput.close();

           return "Success";



    //catch some possible errors...
    } catch (MalformedURLException e) {             
            e.printStackTrace();
        return "Failed";
    } catch (IOException e) {               
            e.printStackTrace();
               return "Failed";
    }
}               

    protected void onProgressUpdate(Integer... progress) {

        notification2.contentView.setProgressBar(R.id.status_progress, 100, progress[0], false);
        String stringy = progress + "%";
        TextView textytext = (TextView) findViewById(R.id.percentage);
        textytext.setText(stringy);
        notificationManager.notify(2, notification2);           
    }

    @Override
    protected void onPostExecute(String result) {
        // TODO Auto-generated method stub                  
        notificationManager.cancel(2);          
    }
}       

Answer 1

你总是发布 0 因为你使用 Integer 来获取进度和 downloadedSize

将其更改为 Double 并尝试 publishProgress((double)(downloadedSize/totalSize))