Downloadmanager in Android

Downloadmanager use

Downloadmanager is a download manager provided by Android

Cons: No support for breakpoint continuation

How to use:

2. To create an instance:

   DownloadManager manager = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);

3. To create a download task:

   Downloadmanager. RequestRequest = new Downloadmanager. Request(Uri. Parse(URL));Specify Save Address Request. Setdestinationinexternalpublicdir("Chuyi","meizhi.apk");Set the network conditions that are allowed to download request. Setallowednetworktypes(Downloadmanager. Request. NETWORK_wifi);Set the behavior of the notification bar request. Setnotificationvisibility(Downloadmanager. Request. VISIBILITY_visible_notify_completed);This download task is uniquely identified by ID long id = Manager. Enqueue(Request);

5. To delete a download task:

   manager.remove(id);

6. Query Download Task:

   Downloadmanager. Queryquery = new Downloadmanager. Query();Query. Setfilterbyid(ID);Cursor cursor = Manager. Query(query);if (cursor. Movetofirst()) {String filename = cursor. getString(cursor. Getcolumnindex(Downloadmanager. COLUMN_local_filename));String Fileuri = cursor. getString(cursor. Getcolumnindex(Downloadmanager. COLUMN_local_uri));Toast. Maketext(Context,"Download Complete ... name:"+filename+", Uri:"+fileuri,toast. LENGTH_short). Show();}else {//todo}cursor. Close();

7. Query Download Progress:

   Downloadmanager. Queryquery = new Downloadmanager. Query(). Setfilterbyid(Downloadid);Cursor c = null;try {c = Downloadmanager. Query(query);if (c! = null && C. Movetofirst()) {int downloadedbytes = c. GetInt(c. Getcolumnindexorthrow(Downloadmanager. COLUMN_bytes_downloaded_so_far));int totalbytes = C. GetInt(c. Getcolumnindexorthrow(Downloadmanager. COLUMN_total_size_bytes));int state = C. GetInt(c. Getcolumnindex(Downloadmanager. COLUMN_status));}} finally {if (c! = null) {C. Close();}}

9. Listen for download end notifications:

   You can listen to the notification of the end of the download by receiving DOWNLOADMANAGER.ACTION_DOWNLOAD_COMPLETE broadcasts

   new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE);    new BroadcastReceiver(){      publicvoidonReceive(Context c,Intent i){          long downId = i.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID,-1);      }    }    context.registerReceiver(mReceiver,filter);

10. Listen for download progress:

    There are three main kinds of programs: 1. Filereceiver 2.ContentObserver 3. Scheduled Tasks

    Class Downloadchangeobserver extends Contentobserver { Public Downloadchangeobserver(){Super(handler);}@Override Public void OnChange(BooleanSelfchange) {//Query Progress}}//in ActivityPrivateDownloadchangeobserver Downloadobserver;@Overrideprotected void onCreate(Bundle savedinstancestate) {Super. OnCreate (Savedinstancestate); Setcontentview (r.layout.download_manager_demo); downloadobserver =NewDownloadchangeobserver ();}@Overrideprotected void Onresume() {Super. Onresume ();/** Observer Download Change **/Getcontentresolver (). Registercontentobserver (Downloadmanagerpro.content_uri,true, downloadobserver);}@Overrideprotected void OnPause() {Super. OnPause (); Getcontentresolver (). Unregistercontentobserver (Downloadobserver);}

    This practice may have some loss of performance, as it will constantly trigger OnChange

    Recommended use of Scheduledexecutorservice

    publicstatic ScheduledExecutorService scheduledExecutorService = Executors.newScheduledThreadPool(3new Runnable() {    @Override    publicvoidrun() {        updateView();    03, TimeUnit.SECONDS);

    Resources:

    1. http://www.trinea.cn/android/android-downloadmanager/
    2. http://www.trinea.cn/android/android-downloadmanager/
    3. Https://github.com/Trinea/android-common/blob/master/src/cn/trinea/android/common/util/DownloadManagerPro.java

Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.

Downloadmanager in Android