java - 无法发布后台 while 循环中异步任务的进度 - Android

Question

我想从 doInBackground 更新对话框的下载进度。
我正在打印日志并发布进度。
他们都没有工作。

它最后更新对话框并最后一次打印所有日志值

private class DownloadEReport extends AsyncTask<String, Void, Void> {
    int progress = 0;

    protected void onPreExecute() {
        mProgressDialog = new ProgressDialog(EReport.this);
        mProgressDialog.setTitle("Downloads");
        mProgressDialog.setMessage("Downloading, Please Wait!");
        mProgressDialog.setIndeterminate(false);
        mProgressDialog.setMax(100);
        mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
        mProgressDialog.setCancelable(false);
        mProgressDialog.show();
    }

    @Override
    protected void onProgressUpdate(Void... values) {
        super.onProgressUpdate(values);
        mProgressDialog.setProgress(progress);
    }



    @Override
    protected Void doInBackground(String... strings) {

        String mUrl = strings[0];
        String json = "";
        int count;
        try {
            URL url = new URL(mUrl);
            URLConnection conection = url.openConnection();
            conection.connect();
            // getting file length
            int lenghtOfFile = conection.getContentLength();

            // input stream to read file - with 8k buffer
            InputStream input = new BufferedInputStream(url.openStream(), 8192);

            // Output stream to write file
            OutputStream output = new FileOutputStream("/sdcard/downloadedfile.txt");

            byte data[] = new byte[1024];
            long total = 0;
            while ((count = input.read(data)) != -1) {
                total += count;
                // writing data to file
                output.write(data, 0, count);

                // publishing the progress....
                // After this onProgressUpdate will be called
                Log.e("JSON Download Progress", "" + (int) ((total * 100) / lenghtOfFile));
                progress = (int) (total * 100 / lenghtOfFile);
                publishProgress();
            }

            // flushing output
            output.flush();
            // closing streams
            output.close();
            input.close();

        } catch (Exception e) {
            Log.e("Error: ", e.getMessage());
        }

        return null;
    }

    @Override
    protected void onPostExecute(Void aVoid) {
        super.onPostExecute(aVoid);
        mProgressDialog.dismiss();
    }
}

Answer 1

从 onProgressUpdate 中删除 super 然后尝试

@Override
protected void onProgressUpdate(Void... values) {
    //super.onProgressUpdate(values);
    mProgressDialog.setProgress(progress);
}

如果它不起作用，请在循环中添加 sleep 语句，以便该循环释放处理器并有时间发布进度

try {
    Thread.sleep(200);
} catch (InterruptedException e) {
    e.printStackTrace();
}