1、DownLoadManager是Android用系统服务(Service)的方式来优化处理长时间的下载操作的一个工具类。避免了我们去处理多线程，通知栏等等。
2、不要忘记添加权限
3、
public class MainActivity extends Activity { private DownloadManager downloadManager; private long downloadId; private TextView mTvMsg; private String downId; private String title; private String address; private String size; private String sizeTotal; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initView(); initData(); } private void initView(){ mTvMsg = (TextView) findViewById(R.id.tv_msg); } private void initData(){ downloadManager = (DownloadManager)getSystemService(DOWNLOAD_SERVICE); String apkUrl = "http://img.meilishuo.net/css/images/AndroidShare/Meilishuo_3.6.1_10006.apk"; DownloadManager.Request request = new DownloadManager.Request(Uri.parse(apkUrl)); // 设置下载地址为sd卡的Trinea文件夹，文件名为MeiLiShuo.apk request.setDestinationInExternalPublicDir("aaaa", "MeiLiShuo.apk"); // 表示允许MediaScanner扫描到这个文件，默认不允许 request.allowScanningByMediaScanner(); // 设置下载中通知栏提示的标题 request.setTitle("MeiLiShuo"); // 设置下载中通知栏提示的介绍 request.setDescription("美丽说"); // 默认只显示下载中通知。VISIBILITY_VISIBLE_NOTIFY_COMPLETED表示下载完成后显示通知栏提示。VISIBILITY_HIDDEN表示不显示任何通知栏提示， // 这个需要在AndroidMainfest中添加权限android.permission.DOWNLOAD_WITHOUT_NOTIFICATION request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED); // 设置下载文件的mineType。因为下载管理Ui中点击某个已下载完成文件及下载完成点击通知栏提示都会根据mimeType去打开文件， // 所以我们可以利用这个属性用于响应点击的打开文件 request.setMimeType("application/cn.trinea.download.file"); // 添加请求下载的网络链接的http头，比如User-Agent，gzip压缩等 // request.addRequestHeader(String header, String value) downloadId = downloadManager.enqueue(request); new Thread(thread).start(); } /** 查询下载任务信息*/ private void queryDownTask(DownloadManager downManager,long id) { DownloadManager.Query query = new DownloadManager.Query(); query.setFilterById(id); Cursor cursor= downManager.query(query); while(cursor.moveToNext()){ downId= cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_ID)); title = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_TITLE)); address = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_LOCAL_URI)); //String statuss = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_STATUS)); size= cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_BYTES_DOWNLOADED_SO_FAR)); sizeTotal = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_TOTAL_SIZE_BYTES)); } cursor.close(); } private Thread thread = new Thread(){ public void run() { while (true) { queryDownTask(downloadManager, downloadId); try { sleep(1000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } handler.sendEmptyMessage(0); } }; }; private Handler handler = new Handler(){ public void handleMessage(android.os.Message msg) { if(msg.what == 0){ mTvMsg.setText(downId + "\n" + title + "\n" + address + "\n" + size + "\n" + sizeTotal); } }; };} 4、下载成功后系统会发出广播DownloadManager.ACTION_DOWNLOAD_COMPLETE，并传递并传递downloadId作为参数。我们可以监听广播来进行下载后的操作。
public class DownloadReceive extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { // TODO Auto-generated method stub long reference = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1); Toast.makeText(context, reference + "", Toast.LENGTH_SHORT).show(); }} 5、有了通知栏其实下载进度可以不用监听的，不过我们还是可以通过DownManager.Query和Cursor查询下载信息。
6、参考博文：http://www.open-open.com/lib/view/open1428024407365.html