Question

我正在使用互联网上的一些代码 - 但我仍然不知道它为什么不起作用...... 如果我拿出Notification的东西，那么它下载得很好（在后台 - 没有好处！）。但每当我加入它们时，它就会强行退出，我不确定为什么！

通知设置

    Intent intent = new Intent(this, ListActivity.class);
    final PendingIntent pendingIntent = PendingIntent.getActivity(getApplicationContext(), 0, intent, 0);

    // configure the notification
    final Notification notification = new Notification(R.drawable.icon, "Downloading Rom via RomGet", System
            .currentTimeMillis());
    notification.flags = notification.flags | Notification.FLAG_ONGOING_EVENT;
    notification.contentView = new RemoteViews(getApplicationContext().getPackageName(), R.layout.layout_download);
    notification.contentIntent = pendingIntent;
    notification.contentView.setImageViewResource(R.id.status_icon, R.drawable.icon_rom);
    notification.contentView.setTextViewText(R.id.download_description, "Downloading");
    notification.contentView.setProgressBar(R.id.download_progress, 100, 0, false);
    notification.icon = R.drawable.ic_stat_rom;

    final NotificationManager notificationManager = (NotificationManager) getApplicationContext().getSystemService(
            getApplicationContext().NOTIFICATION_SERVICE);

    notificationManager.notify(43, notification);

下载课程

    public void run() {         
        try {
            // Setup download things here - all good

            totalSize = urlConnection.getContentLength();

            //create a buffer...
            byte[] buffer = new byte[1024];
            int bufferLength = 0; //used to store a temporary size of the buffer

            //now, read through the input buffer and write the contents to the file
            while ( (bufferLength = inputStream.read(buffer)) > 0 ) {
                //add the data in the buffer to the file in the file output stream (the file on the sd card
                fileOutput.write(buffer, 0, bufferLength);
                //add up the size so we know how much is downloaded
                downloadedSize += bufferLength;
                //this is where you would do something to report the prgress, like this maybe

                handler.sendEmptyMessage(0);
            }
            //close the output stream when done
            fileOutput.close();

        //catch some possible errors...
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        // see http://androidsnippets.com/download-an-http-file-to-sdcard-with-progress-notificationØ
    }

    private Handler handler = new Handler() {

        @Override
        public void handleMessage(Message msg) {
            //notification.setProgressBar(R.id.download_progress, Math.round(totalSize), Math.round(downloadedSize), false);
            notification.contentView.setTextViewText(R.id.download_description, Integer.toString(downloadedSize));
            // inform the progress bar of updates in progress
            notificationManager.notify(43, notification);
        }
    };
}

这是它给我的错误：

05-31 22:48:23.539: DEBUG/AndroidRuntime(24431): Shutting down VM
05-31 22:48:23.539: WARN/dalvikvm(24431): threadid=1: thread exiting with uncaught exception (group=0x40015560)
05-31 22:48:23.542: ERROR/AndroidRuntime(24431): FATAL EXCEPTION: main
05-31 22:48:23.542: ERROR/AndroidRuntime(24431): java.lang.NullPointerException
05-31 22:48:23.542: ERROR/AndroidRuntime(24431):     at com.ezeh.romget.ListActivity$DownloadThread$1.handleMessage(ListActivity.java:285)
05-31 22:48:23.542: ERROR/AndroidRuntime(24431):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-31 22:48:23.542: ERROR/AndroidRuntime(24431):     at android.os.Looper.loop(Looper.java:123)
05-31 22:48:23.542: ERROR/AndroidRuntime(24431):     at android.app.ActivityThread.main(ActivityThread.java:3835)
05-31 22:48:23.542: ERROR/AndroidRuntime(24431):     at java.lang.reflect.Method.invokeNative(Native Method)
05-31 22:48:23.542: ERROR/AndroidRuntime(24431):     at java.lang.reflect.Method.invoke(Method.java:507)
05-31 22:48:23.542: ERROR/AndroidRuntime(24431):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
05-31 22:48:23.542: ERROR/AndroidRuntime(24431):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
05-31 22:48:23.542: ERROR/AndroidRuntime(24431):     at dalvik.system.NativeStart.main(Native Method)
05-31 22:48:23.558: WARN/ActivityManager(13390):   Force finishing activity com.ezeh.romget/.ListActivity
05-31 22:48:24.074: WARN/ActivityManager(13390): Activity pause timeout for HistoryRecord{407e8090 com.ezeh.romget/.ListActivity}
05-31 22:48:29.386: INFO/Process(24431): Sending signal. PID: 24431 SIG: 9
05-31 22:48:29.460: INFO/ActivityManager(13390): Process com.ezeh.romget (pid 24431) has died.
05-31 22:48:29.464: INFO/WindowManager(13390): WIN DEATH: Window{408fbb18 com.ezeh.romget/com.ezeh.romget.ListActivity paused=false}
05-31 22:48:29.468: INFO/DemoService(13809): DiyScheduer.onStart
05-31 22:48:29.468: INFO/ggheart(13809): onStart
05-31 22:48:29.472: INFO/WindowManager(13390): WIN DEATH: Window{40863a78 com.ezeh.romget/com.ezeh.romget.HomeActivity paused=false}
05-31 22:48:29.484: INFO/rxq(13809): onResume()
05-31 22:48:34.644: DEBUG/dalvikvm(24165): GC_EXPLICIT freed 87K, 49% free 3507K/6791K, external 0K/0K, paused 28ms

Answer 1

对于下载时应用程序冻结的新问题，您实际上是通过下载本身来阻止UI过程。解决方法是使用AsyncTask在后台进行下载。 Google介绍了AsyncTasks here。关于如何在线后台下载文件还有很多其他很好的资源。

下载时通知错误

1 个答案: