downloadManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
downloadObserver = new DownloadChangeObserver();
//在執(zhí)行下載前注冊內容監(jiān)聽者
registerContentObserver();
DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
/**設置用于下載時的網絡狀態(tài)*/
request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI | DownloadManager.Request.NETWORK_MOBILE);
/**設置通知欄是否可見*/
request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_HIDDEN);
/**設置漫游狀態(tài)下是否可以下載*/
request.setAllowedOverRoaming(false);
/**如果我們希望下載的文件可以被系統(tǒng)的Downloads應用掃描到并管理，
我們需要調用Request對象的setVisibleInDownloadsUi方法，傳遞參數true.*/
request.setVisibleInDownloadsUi(true);
/**設置文件保存路徑*/
request.setDestinationInExternalFilesDir(getApplicationContext(), "phoenix", "phoenix.apk");
/**將下載請求放入隊列， return下載任務的ID*/
downloadId = downloadManager.enqueue(request);
//執(zhí)行下載任務時注冊廣播監(jiān)聽下載成功狀態(tài)
registerBroadcast();

<!--網絡通信權限-->
<uses-permission android:name="android.permission.INTERNET"/>
<!--SD卡寫入數據權限-->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<!--SD卡創(chuàng)建與刪除權限-->
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
<!--VISIBILITY_HIDDEN表示不顯示任何通知欄提示的權限-->
<uses-permission android:name="android.permission.DOWNLOAD_WITHOUT_NOTIFICATION"/>
<!--DownloadManager-->
<uses-permission android:name="android.permission.ACCESS_DOWNLOAD_MANAGER"/>
在清單文件中注冊Service
<!--版本更新服務-->
<service android:name="com.github.phoenix.service.DownloadService"></service>

/**
* 注冊ContentObserver
*/
private void registerContentObserver() {
 /** observer download change **/
 if (downloadObserver != null) {
   getContentResolver().registerContentObserver(Uri.parse("content://downloads/my_downloads"), true, downloadObserver);
 }
}

/**
* 監(jiān)聽下載進度
*/
private class DownloadChangeObserver extends ContentObserver {

 public DownloadChangeObserver() {
   super(downLoadHandler);
   scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();
 }

 /**
  * 當所監(jiān)聽的Uri發(fā)生改變時，就會回調此方法
  *
  * @param selfChange 此值意義不大, 一般情況下該回調值false
  */
 @Override
 public void onChange(boolean selfChange) {
   scheduledExecutorService.scheduleAtFixedRate(progressRunnable, 0, 2, TimeUnit.SECONDS);
 }
}
/**
* 通過query查詢下載狀態(tài)，包括已下載數據大小，總大小，下載狀態(tài)
*
* @param downloadId
* @return
*/
private int[] getBytesAndStatus(long downloadId) {
 int[] bytesAndStatus = new int[]{
     -1, -1, 0
 };
 DownloadManager.Query query = new DownloadManager.Query().setFilterById(downloadId);
 Cursor cursor = null;
 try {
   cursor = downloadManager.query(query);
   if (cursor != null && cursor.moveToFirst()) {
     //已經下載文件大小
     bytesAndStatus[0] = cursor.getInt(cursor.getColumnIndexOrThrow(DownloadManager.COLUMN_BYTES_DOWNLOADED_SO_FAR));
     //下載文件的總大小
     bytesAndStatus[1] = cursor.getInt(cursor.getColumnIndexOrThrow(DownloadManager.COLUMN_TOTAL_SIZE_BYTES));
     //下載狀態(tài)
     bytesAndStatus[2] = cursor.getInt(cursor.getColumnIndex(DownloadManager.COLUMN_STATUS));
   }
 } finally {
   if (cursor != null) {
     cursor.close();
   }
 }
 return bytesAndStatus;
}

private ServiceConnection conn = new ServiceConnection() {

 @Override
 public void onServiceConnected(ComponentName name, IBinder service) {
   DownloadService.DownloadBinder binder = (DownloadService.DownloadBinder) service;
   DownloadService downloadService = binder.getService();

   //接口回調，下載進度
   downloadService.setOnProgressListener(new DownloadService.OnProgressListener() {
     @Override
     public void onProgress(float fraction) {
       LogUtil.i(TAG, "下載進度：" + fraction);
       bnp.setProgress((int)(fraction * 100));

       //判斷是否真的下載完成進行安裝了，以及是否注冊綁定過服務
       if (fraction == DownloadService.UNBIND_SERVICE && isBindService) {
         unbindService(conn);
         isBindService = false;
         MToast.shortToast("下載完成！");
       }
     }
   });
 }

 @Override
 public void onServiceDisconnected(ComponentName name) {

 }
};

/**
* 安裝APK
* @param context
* @param apkPath 安裝包的路徑
*/
public static void installApk(Context context, Uri apkPath) {
 Intent intent = new Intent();
 intent.setAction(Intent.ACTION_VIEW);
 //此處因為上下文是Context，所以要加此Flag，不然會報錯
 intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
 intent.setDataAndType(apkPath, "application/vnd.android.package-archive");
 context.startActivity(intent);
}

/**
* 刪除上次更新存儲在本地的apk
*/
private void removeOldApk() {
 //獲取老ＡＰＫ的存儲路徑
 File fileName = new File(SPUtil.getString(Constant.SP_DOWNLOAD_PATH, ""));
 LogUtil.i(TAG, "老APK的存儲路徑 =" + SPUtil.getString(Constant.SP_DOWNLOAD_PATH, ""));

 if (fileName != null && fileName.exists() && fileName.isFile()) {
   fileName.delete();
   LogUtil.i(TAG, "存儲器內存在老APK，進行刪除操作");
 }
}