android 四大组件之Service 结合通知

Posted 2020-07-30

　　 由于Service运行在后台， 一旦运行，使用Toast Notifications 和 Status Bar Notification

来通知客户。

Service结合通知和用户交互：

public class DownloadService extends Service {
    private String uri;
    //通知管理器
    private NotificationManager nmanager;
    private Notification.Builder builder ;
    @Override
    public void onCreate() {
        super.onCreate();
        getNotification();
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        uri = intent.getStringExtra("uri");
        //启动下载进程
        new Thread(new MyRunnable()).start();
        return START_STICKY ;
    }
    /**
     *  下载放在线程中执行，
     *  
     */
    public class MyRunnable implements Runnable {
        @Override
        public void run() {
            //读取的数据存储
            byte[]  result = null;
            HttpClient client = new DefaultHttpClient();
            try {
                Log.i("tag", "uri>>"+uri);
                HttpGet get = new HttpGet(uri);
                HttpResponse response = client.execute(get);
                HttpEntity entity = response.getEntity();
                int stateCode = response.getStatusLine().getStatusCode();
                if(stateCode != 200){
                    Log.i("tag", stateCode+"-->下载失败-->");
                }
                //获取网络输入流
                InputStream in = entity.getContent();
                //获取网路数据总长度
                long total  = entity.getContentLength();
                byte[] bs = new byte[10];
                int len_per = 0;//每次读取的长度，
                ByteArrayOutputStream baos = new  ByteArrayOutputStream();
                int readedLen = 0;//已经读取的数据量
                while((len_per = in.read(bs)) != -1){
                    baos.write(bs, 0, len_per);
                    readedLen += len_per;
　　　　　　　　　　　 //将进度消息发送给handler, 在handler中更新进度
          int progress = (int) ((readedLen*100)/(float)total);
             Message msg = Message.obtain();
             msg.arg1 = progress;
             handler.sendMessage(msg);
                }
                result = baos.toByteArray();
　　　　　　　　　 //通知完成
                handler.sendEmptyMessage(1);
            }catch(Exception e){
                e.printStackTrace();
            }finally {
                if(client != null){
                    client.getConnectionManager().shutdown();
                }
            }
        }
    }
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
    /**
     * 更新UI
     */
    private Handler handler = new Handler() {
        public void handleMessage(Message msg) {
            //更新UI
            builder.setProgress(100, msg.arg1, false);
            nmanager.notify(1001, builder.build());
            if(msg.what == 1){
                //下载完成
                Toast.make(getapplicationContext(), "下载完成", 1).show();s
            }
        }
    };
    /**
     *通知初始化
     */
    private void getNotification() {
        nmanager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        builder = new Notification.Builder(getApplicationContext());
        builder.setSmallIcon(R.drawable.ic_launcher);
        builder.setTicker("通知来了");
        builder.setContentTitle("下载");
        builder.setContentText("正在下载。。。。。");
    }

}