ReadingNotes@02-12-2013

ReadingNotes@02-12-2013

ReadingNotes@02-12-2013

Cheatsheet: 2013 04.17 ~ 04.30

一直都比较喜欢CheatSheet形式的reference,简单明了。

这个不错Android cheatsheet for graphic designers

C++ Macro

http://stackoverflow.com/questions/216875/in-macros

One thing to be aware of when you're using the token-paste ('##') or stringizing ('#') preprocessing operators is that you have to use an extra level of indirection for them to work properly in all cases

实现类似android市场多apk同时下载,更新通知栏信息小结

public class UpdateService extends Service {
    private NotificationManager nm;
    private Notification notification;
    private boolean cancelUpdate = false;
    private MyHandler myHandler;
    private static ExecutorService executorService = Executors.newFixedThreadPool(5); // 固定五个线程来执行任务
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onStart(Intent intent, int startId) {
        super.onStart(intent, startId);
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        nm = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        /*同一个服务,为避免通知栏起冲突,特使用应用的id作为通知栏id,并用application中的一个Map记录id和下载进度,
        并通过handler操作*/
        int notificationId = intent.getIntExtra("id", new Random().nextInt());
        if(Constants.download.containsKey(notificationId))
            return 0;
        notification = new Notification();
        notification.icon = android.R.drawable.stat_sys_download;
        // notification.icon=android.R.drawable.stat_sys_download_done;
        notification.tickerText = intent.getStringExtra("name")+"开始下载";
        notification.when = System.currentTimeMillis();
        notification.defaults = Notification.DEFAULT_LIGHTS;
        //显示在“正在进行中”
        notification.flags = Notification.FLAG_NO_CLEAR | Notification.FLAG_ONGOING_EVENT;
        PendingIntent contentIntent = PendingIntent.getActivity(this, notificationId,new Intent(this, IndexActivity.class), 0);
        notification.setLatestEventInfo(this, intent.getStringExtra("name"), "0%", contentIntent);
        Constants.download.put(notificationId, 0);
        // 将下载任务添加到任务栏中
        nm.notify(notificationId, notification);
        myHandler = new MyHandler(Looper.myLooper(), UpdateService.this);
        //myHandler = new MyHandler(Looper.myLooper(), this);

        // 初始化下载任务内容views
        //Message message = myHandler.obtainMessage(3, 0);
        //myHandler.sendMessage(message);

        // 启动线程开始执行下载任务
        downFile(intent.getStringExtra("url"),notificationId,intent.getStringExtra("name"));
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
    }

    // 下载更新文件
    private void downFile(final String url,final int notificationId,final String name) {
        executorService.execute(new Runnable() {
            @Override
            public void run() {
                // TODO Auto-generated method stub
                File tempFile = null;
                try {
                    HttpClient client = new DefaultHttpClient();
                    // params[0]代表连接的url
                    HttpGet get = new HttpGet(url);
                    HttpResponse response = client.execute(get);
                    HttpEntity entity = response.getEntity();
                    long length = entity.getContentLength();
                    InputStream is = entity.getContent();
                    if (is != null) {
                        File rootFile = new File(Environment.getExternalStorageDirectory(),"/zhtrade");
                        if (!rootFile.exists() && !rootFile.isDirectory())
                            rootFile.mkdir();

                        /*
                         * 路径的特殊性,分解出包名,并用对应的应用"_"+id特别标识,避免出现apk包重复和冲突(有一些apk的package是相同的)
                         */
                        tempFile = new File(Environment.getExternalStorageDirectory(),"/zhtrade/"+ url.substring(url.lastIndexOf("/"),url.indexOf("?"))+"_"+notificationId+".apk");
                        if (tempFile.exists())
                            tempFile.delete();
                        tempFile.createNewFile();

                        // 已读出流作为参数创建一个带有缓冲的输出流
                        BufferedInputStream bis = new BufferedInputStream(is);

                        // 创建一个新的写入流,讲读取到的图像数据写入到文件中
                        FileOutputStream fos = new FileOutputStream(tempFile);
                        // 已写入流作为参数创建一个带有缓冲的写入流
                        BufferedOutputStream bos = new BufferedOutputStream(fos);

                        int read;
                        long count = 0;
                        int precent = 0;
                        byte[] buffer = new byte[1024];
                        while ((read = bis.read(buffer)) != -1 && !cancelUpdate) {
                            bos.write(buffer, 0, read);
                            count += read;
                            precent = (int) (((double) count / length) * 100);

                            // 每下载完成10%就通知任务栏进行修改下载进度
                            if (precent - Constants.download.get(notificationId) >= 10) {
                                Constants.download.put(notificationId, precent);
                                Message message = myHandler.obtainMessage(3,precent);
                                Bundle bundle = new Bundle();
                                bundle.putString("name", name);
                                message.setData(bundle);
                                message.arg1 = notificationId;
                                myHandler.sendMessage(message);
                            }
                        }
                        bos.flush();
                        bos.close();
                        fos.flush();
                        fos.close();
                        is.close();
                        bis.close();
                    }

                    if (!cancelUpdate) {
                        Message message = myHandler.obtainMessage(2, tempFile);
                        message.arg1 = notificationId;
                        Bundle bundle = new Bundle();
                        bundle.putString("name", name);
                        message.setData(bundle);
                        myHandler.sendMessage(message);
                    } else {
                        tempFile.delete();
                    }
                } catch (ClientProtocolException e) {
                    if (tempFile.exists())
                        tempFile.delete();
                    Message message = myHandler.obtainMessage(4, name+"下载失败:网络异常!");
                    message.arg1 = notificationId;
                    myHandler.sendMessage(message);
                } catch (IOException e) {
                    if (tempFile.exists())
                        tempFile.delete();
                    Message message = myHandler.obtainMessage(4, name+"下载失败:文件存储异常");
                    message.arg1 = notificationId;
                    myHandler.sendMessage(message);
                } catch (Exception e) {
                    if (tempFile.exists())
                        tempFile.delete();
                    Message message = myHandler.obtainMessage(4, name+"下载失败,"+e.getMessage());
                    message.arg1 = notificationId;
                    myHandler.sendMessage(message);
                }
            }
        });
    }

    // 安装下载后的apk文件
    private void Instanll(File file, Context context) {
        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        intent.setAction(android.content.Intent.ACTION_VIEW);
        intent.setDataAndType(Uri.fromFile(file),"application/vnd.android.package-archive");
        context.startActivity(intent);
    }

    /* 事件处理类 */
    class MyHandler extends Handler {
        private Context context;

        public MyHandler(Looper looper, Context c) {
            super(looper);
            this.context = c;
        }

        @Override
        public void handleMessage(Message msg) {
            PendingIntent contentIntent = null;
            super.handleMessage(msg);
            if (msg != null) {
                switch (msg.what) {
                case 0:
                    Toast.makeText(context, msg.obj.toString(),Toast.LENGTH_SHORT).show();
                    Constants.download.remove(msg.arg1);
                    break;
                case 1:
                    break;
                case 2:
                    contentIntent = PendingIntent.getActivity(UpdateService.this, msg.arg1,new Intent(UpdateService.this, IndexActivity.class), 0);
                    notification.setLatestEventInfo(UpdateService.this, msg.getData().getString("name")+"下载完成",   "100%",contentIntent);
                    nm.notify(msg.arg1, notification);
                    // 下载完成后清除所有下载信息,执行安装提示
                    Constants.download.remove(msg.arg1);
                    nm.cancel(msg.arg1);
                    Instanll((File) msg.obj, context);
                    // 停止掉当前的服务
                    stopSelf();
                    break;
                case 3:
                     contentIntent = PendingIntent.getActivity(UpdateService.this, msg.arg1,new Intent(UpdateService.this, IndexActivity.class), 0);
                    notification.setLatestEventInfo(UpdateService.this, msg.getData().getString("name")+"正在下载",  Constants.download.get(msg.arg1) + "%",contentIntent);
                    nm.notify(msg.arg1, notification);
                    break;
                case 4:
                    Toast.makeText(context, msg.obj.toString(),Toast.LENGTH_SHORT).show();
                    Constants.download.remove(msg.arg1);
                    nm.cancel(msg.arg1);
                    stopSelf();
                    break;
                }
            }
        }
    }
    
}

Post by: Jalen Wang (转载请注明出处)

posted on 2013-05-03 09:11  Jalen Wang  阅读(215)  评论(0编辑  收藏  举报

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