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我创建了一个从前台服务下载文件的演示，并在通知进度栏中显示下载进度。我在服务中使用 asynctask，在 asynctask 中我使用 HttpUrlConnection 从 Internet 下载文件并在 onProgressUpdate() 中更新进度。我显示以下错误 跳过 145 帧！应用程序可能在其主线程上做了太多工作。

和电话被绞死。

Service.java

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    Log.d(TAG + "===", "onStartCommand");
    String downloadUrl = "", downloadFileName = "";
    Bundle bundle = intent.getExtras();
    if (bundle != null) {
        downloadUrl = bundle.getString("download_url");
        downloadFileName = bundle.getString("download_filename");
    }
    handler = new Handler();
    if (intent.getAction().equalsIgnoreCase(START_DOWNLOAD)) {

        Intent notificationIntent = new Intent(mContext, MainActivity.class);
        notificationIntent.setAction(MAIN_ACTION);
        notificationIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
        PendingIntent pendingIntent = PendingIntent.getActivity(mContext, 0, notificationIntent, 0);

        Intent pauseIntent = new Intent(mContext, DownloadService.class);
        pauseIntent.setAction(PAUSE_DOWNLOAD);
        PendingIntent pausePendingIntent = PendingIntent.getService(mContext, 0, pauseIntent, 0);

        Intent stopIntent = new Intent(mContext, DownloadService.class);
        stopIntent.setAction(STOP_DOWNLOAD);
        PendingIntent stopPendingIntent = PendingIntent.getService(mContext, 0, stopIntent, 0);

        mNotiManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);

        builder = new NotificationCompat.Builder(mContext)
                .setContentTitle("Download demo")
                .setTicker("downloading...")
                .setSmallIcon(R.mipmap.ic_launcher)
                .setOngoing(true)
                .setContentIntent(pendingIntent)
                .addAction(R.drawable.ic_pause_download, "pause", pausePendingIntent)
                .addAction(R.drawable.ic_cancel_download, "stop", stopPendingIntent);
        notification = builder.build();
        startForeground(DOWNLOAD_NOTIFICATION, notification);

        new DownloadFileAsync(downloadUrl, downloadFileName).execute();

    } else if (intent.getAction().equalsIgnoreCase(PAUSE_DOWNLOAD)) {
        Toast.makeText(mContext.getApplicationContext(), "Download Pause !", Toast.LENGTH_LONG).show();

    } else if (intent.getAction().equalsIgnoreCase(STOP_DOWNLOAD)) {
        Toast.makeText(mContext.getApplicationContext(), "Download Stop !", Toast.LENGTH_LONG).show();
        mNotiManager.cancel(DOWNLOAD_NOTIFICATION);
        stopForeground(true);
        stopSelf();
    }

    return START_STICKY;
}

和我的异步任务

private class DownloadFileAsync extends AsyncTask<Void, Integer, Void> {
    private HttpURLConnection mUrlConnection;
    private File downloadFile = null;
    private String downloadUrl = "";
    private String downloadFileName = "";

    public DownloadFileAsync(String downloadUrl, String downloadFileName) {
        this.downloadUrl = downloadUrl;
        this.downloadFileName = downloadFileName;
    }

    @Override
    protected Void doInBackground(Void... objects) {
        try {
            URL url = new URL(downloadUrl);
            mUrlConnection = (HttpURLConnection) url.openConnection();
            mUrlConnection.setRequestMethod("GET");
            mUrlConnection.setDoOutput(true);
            mUrlConnection.setReadTimeout(20 * 1000);
            mUrlConnection.setConnectTimeout(20 * 1000);
            mUrlConnection.connect();
            int responseCode = mUrlConnection.getResponseCode();
            Log.e("Response Code===", responseCode + "");
            if (responseCode == HttpURLConnection.HTTP_OK) {
                mDownloadMaxSize = Long.parseLong(mUrlConnection.getHeaderField("content-length"));
                downloadFile = new File(Environment.getExternalStorageDirectory(), downloadFileName);
                if (!downloadFile.exists()) {
                    downloadFile.createNewFile();
                } else {
                    long length = downloadFile.length();
                    mUrlConnection.setRequestProperty("Request", "bytes = " + length + "-");
                }
                InputStream in = new BufferedInputStream(mUrlConnection.getInputStream());
                DataInputStream dis = new DataInputStream(in);
                FileOutputStream fos = new FileOutputStream(downloadFile, true);
                byte buffer[] = new byte[1024];
                int length;

                while ((length = dis.read(buffer)) > 0) {
                    fos.write(buffer, 0, length);
                    mDownloadProgress += length;
                    publishProgress((int) (mDownloadProgress * 100 / mDownloadMaxSize));
                }
                in.close();
                fos.close();
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (mUrlConnection != null) {
                mUrlConnection.disconnect();
            }
        }
        return null;
    }

    @Override
    protected void onProgressUpdate(Integer... values) {
        super.onProgressUpdate(values);

        builder.setProgress(100, values[0], false);
        mNotiManager.notify(DOWNLOAD_NOTIFICATION, builder.build());
    }

    @Override
    protected void onPostExecute(Void aVoid) {
        super.onPostExecute(aVoid);
        builder.setProgress(0, 0, false);
        mNotiManager.notify(DOWNLOAD_NOTIFICATION, builder.build());

    }
}

请帮助我我能做些什么来解决这个问题。提前致谢。

4

1 回答 1

0

你的代码很好。只需在后台方法中放置一些延迟，看看您是否可以看到任何变化。

于 2017-05-04T10:19:14.100 回答