Question

我想更新进度对话框的下载进度，但AsyncTask在使用 BufferedReader 时会挂起。未调用 publishProgress 而未在 onProgressUpdate 中更新进度对话框。此外，它不会在循环中打印Log。

我已经使用打印测试登录我的代码。

First Log正在LogCat
第二个日志未打印

第三个日志也不打印而不执行方法的 publishProgress

private class GetData extends AsyncTask<String, Integer, String>{
    private ProgressDialog dialog;
    @Override
    protected void onPreExecute() {
        super.onPreExecute();

        dialog = new ProgressDialog(HomeScreen.this);
        dialog.setTitle("Be Patient");
        dialog.setMessage("Loading data for first time use only. Please don't close the application.");
        dialog.setCancelable(false);
        dialog.setIndeterminate(true);
        dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
        dialog.show();
    }

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

        dialog.setIndeterminate(false);
        dialog.setMax(100);
        dialog.setProgress(progress[0]);
    }

    @Override
    protected String doInBackground(String... params) {

        String serverResponse = null;
        BufferedReader in = null;
        java.net.URL myLink;

        try {
            Log.e("AsyncTask", "This log is printing");
            myLink = new java.net.URL(params[0]);
            in = new BufferedReader(new InputStreamReader(myLink.openStream()));
            Log.e("AsyncTask", "This log not printing");
            String inputLine;
            StringBuilder response = new StringBuilder();
            while ((inputLine = in.readLine()) != null) {
                response.append(inputLine);
                publishProgress(50);  // Not executing : Default value set is 50 just for cheecking.
                Log.d("AsyncTask", "This log also not printing & publishProgress not executing");
            }
            serverResponse = response.toString();

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (in != null) in.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return serverResponse;
    }

    @Override
    protected void onPostExecute(String result) {
        super.onPostExecute(result);

        if (!HomeScreen.this.isFinishing() && dialog != null) {
            dialog.dismiss();
        }
    }
}

使用BufferedReader时，AsyncTask publishProgress不会在onProgressUpdate上更新

0 个答案: