Android 下载百分比显示负值

我正在使用线程下载文件表单服务器。我已经按照下面提到的代码下载了文件

下载线程：：

这是我的活动处理程序

现在下载文件时，我得到的百分比值为负数

请注意，在测试期间，我在摩托罗拉G设备和Micromax设备中发现了奇怪的问题，该设备显示的百分比为负值，这在三星设备中是不存在的

有什么想法吗

---

提前非常感谢……

您没有说出许多msg.what中的哪个显示负值。发送前是否检查了值？使用Log.d检查。@greenapps在网上搜索并调试代码后，我发现URLConnection.getContentLength返回-1值，因此我的下载百分比显示为负值。但奇怪的是，在Moto G中测试时，如果我使用组织的wifi网络下载文件，我可以得到文件大小，但如果我使用我的个人数据连接，它会返回-1。

public class DownloaderThread extends Thread
    {
        // constants
        private static final int DOWNLOAD_BUFFER_SIZE = 4096;

        // instance variables
        //private SettingsListFragment parentActivity;
        private String downloadUrl;

        /**
         * Instantiates a new DownloaderThread object.
         * @param inUrl String representing the URL of the file to be downloaded.
         */
        public DownloaderThread(String inUrl)
        {
            downloadUrl = "";
            if(inUrl != null)
            {
                downloadUrl = inUrl;
            }
            //parentActivity = inParentActivity;
        }

        /**
         * Connects to the URL of the file, begins the download, and notifies the
         * AndroidFileDownloader activity of changes in state. Writes the file to
         * the root of the SD card.
         */
        @Override
        public void run()
        {
            URL url;
            URLConnection conn;
            int fileSize, lastSlash;
            String fileName;
            BufferedInputStream inStream;
            BufferedOutputStream outStream;
            File outFile;
            FileOutputStream fileStream;
            Message msg;

            // we're going to connect now
            msg = Message.obtain(activityHandler,MESSAGE_CONNECTING_STARTED,0, 0, downloadUrl);
            activityHandler.sendMessage(msg);

            try
            {
                url = new URL(downloadUrl);
                conn = url.openConnection();
                conn.setUseCaches(false);
                fileSize = conn.getContentLength();

                // get the filename
                lastSlash = url.toString().lastIndexOf('/');
                fileName = "file.bin";
                if(lastSlash >=0)
                {
                    fileName = url.toString().substring(lastSlash + 1);
                }
                if(fileName.equals(""))
                {
                    fileName = "file.bin";
                }

                // notify download start
                int fileSizeInKB = fileSize / 1024;
                if(Utils.getAvailableExternalMemorySize() > fileSizeInKB)
                {
                    msg = Message.obtain(activityHandler,MESSAGE_DOWNLOAD_STARTED,fileSizeInKB, 0, fileName);
                    activityHandler.sendMessage(msg);

                    // start download
                    inStream = new BufferedInputStream(conn.getInputStream());
                    outFile = new File(Environment.getExternalStorageDirectory() + "/" + fileName);
                    System.out.println("#### Download File Location==>"+outFile);
                    fileStream = new FileOutputStream(outFile);
                    outStream = new BufferedOutputStream(fileStream, DOWNLOAD_BUFFER_SIZE);
                    byte[] data = new byte[DOWNLOAD_BUFFER_SIZE];
                    int bytesRead = 0, totalRead = 0;
                    while(!isInterrupted() && (bytesRead = inStream.read(data, 0, data.length)) >= 0)
                    {
                        outStream.write(data, 0, bytesRead);

                        long total = 0;
                        // update progress bar
                        totalRead += bytesRead;
                        int totalReadInKB = totalRead / 1024;
                        int percentage=(int)((totalRead*100)/fileSize);
                        //msg = Message.obtain(activityHandler,MESSAGE_UPDATE_PROGRESS_BAR,totalReadInKB, 0);
                        msg = Message.obtain(activityHandler,MESSAGE_UPDATE_PROGRESS_BAR,totalReadInKB, percentage);
                        activityHandler.sendMessage(msg);
                    }

                    outStream.close();
                    fileStream.close();
                    inStream.close();

                    if(isInterrupted())
                    {
                        // the download was canceled, so let's delete the partially downloaded file
                        outFile.delete();
                    }
                    else
                    {
                        // notify completion
                        msg = new Message();
                        msg.what=MESSAGE_DOWNLOAD_COMPLETE;
                        msg.obj=fileName;
                        msg.obj=outFile;
                        //msg = Message.obtain(parentActivity.activityHandler,
                        //AndroidFileDownloader.MESSAGE_DOWNLOAD_COMPLETE);
                        activityHandler.sendMessage(msg);
                    }
                }
                else
                {
                    String errMsg = getActivity().getString(R.string.msg_error_insufficient_storage);
                    msg = Message.obtain(activityHandler,MESSAGE_ENCOUNTERED_ERROR,0, 0, errMsg);
                    activityHandler.sendMessage(msg);
                }
            }
            catch(MalformedURLException e)
            {
                String errMsg = getActivity().getString(R.string.msg_error_message_bad_url);
                msg = Message.obtain(activityHandler,MESSAGE_ENCOUNTERED_ERROR,0, 0, errMsg);
                activityHandler.sendMessage(msg);
            }
            catch(FileNotFoundException e)
            {
                String errMsg = getActivity().getString(R.string.msg_error_message_file_not_found);
                msg = Message.obtain(activityHandler,MESSAGE_ENCOUNTERED_ERROR,0, 0, errMsg);
                activityHandler.sendMessage(msg); 
            }
            catch(Exception e)
            {
                String errMsg = getString(R.string.msg_error_message_general);
                msg = Message.obtain(activityHandler,MESSAGE_ENCOUNTERED_ERROR,0, 0, errMsg);
                activityHandler.sendMessage(msg); 
            }
        }
    }

public Handler activityHandler = new Handler()
    {
        public void handleMessage(Message msg)
        {
            switch(msg.what)
            {
            /*
             * Handling MESSAGE_UPDATE_PROGRESS_BAR:
             * 1. Get the current progress, as indicated in the arg1 field
             *    of the Message.
             * 2. Update the progress bar.
             */
            case MESSAGE_UPDATE_PROGRESS_BAR:
                if(downloading.progress != null)
                {
                    int currentProgress = msg.arg1;
                    int percentage=msg.arg2;
                    System.out.println("current Progrss=>"+currentProgress);
                    System.out.println(" % =>"+percentage);
                    if(downloading.tvPercentage!=null)
                    {
                        downloading.tvPercentage.setText(String.valueOf(percentage) + " %");
                    }
                    downloading.progress.setProgress(currentProgress);
                }
                break;

                /*
                 * Handling MESSAGE_CONNECTING_STARTED:
                 * 1. Get the URL of the file being downloaded. This is stored
                 *    in the obj field of the Message.
                 * 2. Create an indeterminate progress bar.
                 * 3. Set the message that should be sent if user cancels.
                 * 4. Show the progress bar.
                 */
            case MESSAGE_CONNECTING_STARTED:
                if(msg.obj != null && msg.obj instanceof String)
                {
                    System.out.println("MESSAGE_CONNECTING_STARTED ==>"+msg.toString());
                    String url = (String) msg.obj;
                    // truncate the url
                    if(url.length() > 16)
                    {
                        String tUrl = url.substring(0, 15);
                        tUrl += "...";
                        url = tUrl;
                    }
                    String pdTitle = getActivity().getString(R.string.msg_progress_dialog_title_connecting);
                    String pdMsg = getActivity().getString(R.string.msg_progress_dialog_message_prefix_connecting);
                    pdMsg += " " + url;

                    dismissCurrentProgressDialog();

                    if(pd.isShowing())
                    {
                        pd.dismiss();
                    }

                    progressDialog = new ProgressDialog(context);
                    progressDialog.setTitle(pdTitle);
                    progressDialog.setMessage(pdMsg);
                    progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
                    progressDialog.setIndeterminate(true);
                    // set the message to be sent when this dialog is canceled
                    Message newMsg = Message.obtain(this, MESSAGE_DOWNLOAD_CANCELED);
                    progressDialog.setCancelMessage(newMsg);
                    progressDialog.show();
                }
                break;

                /*
                 * Handling MESSAGE_DOWNLOAD_STARTED:
                 * 1. Create a progress bar with specified max value and current
                 *    value 0; assign it to progressDialog. The arg1 field will
                 *    contain the max value.
                 * 2. Set the title and text for the progress bar. The obj
                 *    field of the Message will contain a String that
                 *    represents the name of the file being downloaded.
                 * 3. Set the message that should be sent if dialog is canceled.
                 * 4. Make the progress bar visible.
                 */
            case MESSAGE_DOWNLOAD_STARTED:
                // obj will contain a String representing the file name
                if(msg.obj != null && msg.obj instanceof String)
                {
                    System.out.println("Download Started ==>"+msg.toString());
                    int maxValue = msg.arg1;
                    String fileName = (String) msg.obj;
                    String pdTitle = getActivity().getString(R.string.msg_progress_dialog_title_downloading);
                    String pdMsg = getActivity().getString(R.string.msg_progress_dialog_message_prefix_downloading);
                    pdMsg += " " + fileName;

                    dismissCurrentProgressDialog();
                    downloading=new custom_progressDialog(getActivity());
                    downloading.setCanceledOnTouchOutside(false);
                    downloading.progress.setProgress(0);
                    downloading.progress.setMax(maxValue);
                    downloading.show();
                    // set the message to be sent when this dialog is canceled
                    Message newMsg = Message.obtain(this, MESSAGE_DOWNLOAD_CANCELED);
                    /*progressDialog.setCancelMessage(newMsg);
                    progressDialog.setCancelable(true);
                    progressDialog.setCanceledOnTouchOutside(false);
                    progressDialog.show();*/
                }
                break;

                /*
                 * Handling MESSAGE_DOWNLOAD_COMPLETE:
                 * 1. Remove the progress bar from the screen.
                 * 2. Display Toast that says download is complete.
                 */
            case MESSAGE_DOWNLOAD_COMPLETE:
                final String downloadedFilePath=msg.obj.toString();
                dismissCurrentProgressDialog();

                if(pd!=null && pd.isShowing())
                {
                    pd.dismiss();
                }

                download_successfulDialog successfulDialg=new download_successfulDialog(getActivity(),downloadedFilePath);
                successfulDialg.setCanceledOnTouchOutside(false);
                successfulDialg.show();
                //displayMessage(getString(R.string.user_message_download_complete));
                //displayMessage("File has been successfully download at "+downloadedFilePath);

                break;

                /*
                 * Handling MESSAGE_DOWNLOAD_CANCELLED:
                 * 1. Interrupt the downloader thread.
                 * 2. Remove the progress bar from the screen.
                 * 3. Display Toast that says download is complete.
                 */
            case MESSAGE_DOWNLOAD_CANCELED:
                if(downloaderThread != null)
                {
                    downloaderThread.interrupt();
                }
                dismissCurrentProgressDialog();

                if(pd!=null && pd.isShowing())
                {
                    pd.dismiss();
                }

                //displayMessage()
                displayMessage(getString(R.string.msg_user_message_download_canceled));
                break;

                /*
                 * Handling MESSAGE_ENCOUNTERED_ERROR:
                 * 1. Check the obj field of the message for the actual error
                 *    message that will be displayed to the user.
                 * 2. Remove any progress bars from the screen.
                 * 3. Display a Toast with the error message.
                 */
            case MESSAGE_ENCOUNTERED_ERROR:
                // obj will contain a string representing the error message
                if(msg.obj != null && msg.obj instanceof String)
                {
                    String errorMessage = (String) msg.obj;
                    dismissCurrentProgressDialog();

                    if(pd!=null && pd.isShowing())
                    {
                        pd.dismiss();
                    }

                    displayMessage(errorMessage);
                }
                break;

            default:
                // nothing to do here
                break;
            }
        }
    };