小编Mat*_*ber的帖子

我试图用asyncTask下载一个文件,但是没有工作,没有错误消息或什么都没有,只是不下载文件...我尝试了一切,但它似乎没有进入的同时...任何人都知道什么可以是问题？我在手机上测试过,网址也可以.

class DownloadFileFromURL extends AsyncTask<String, String, String> {

    /**
     * Before starting background thread
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        System.out.println("Starting download");
    }

    /**
     * Downloading file in background thread
     * */
    @Override
    protected String doInBackground(String... f_url) {
        int count;
        try {
            String root = Environment.getExternalStorageDirectory().toString();

            System.out.println("Downloading");
            URL url = new URL(f_url[0]);

            URLConnection conection = url.openConnection();
            conection.connect();
            // getting file length
            int lenghtOfFile = conection.getContentLength();

            // input stream to read file - with 8k buffer
            InputStream input = …