【移動應用開發(fā)技術】Android-Download(下載)項目詳解

Download(下載)項目詳解本文地址:

/caroline_wendy/article/details/22280461環(huán)境:Android0.5.2+gradle1.11+kindlefireDownload,下載項目,從Internet上下載資源,并存入本地SD卡.點擊Download按鈕,下載圖片,然后顯示下載內容,可以點擊查看.Download的具體設計:位置:res->layout->activity_main.xml<RelativeLayoutxmlns:android="/apk/res/android"xmlns:tools="/tools"android:layout_width="match_parent"android:layout_height="match_parent"android:paddingLeft="@dimen/activity_horizontal_margin"android:paddingRight="@dimen/activity_horizontal_margin"android:paddingTop="@dimen/activity_vertical_margin"android:paddingBottom="@dimen/activity_vertical_margin"tools:context="mzx.spike.download.app.MainActivity"><Buttonandroid:id="@+id/download_button"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="Download"/><TextViewandroid:text="@string/hello_world"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@id/download_button"/></RelativeLayout>位置:main->AndroidManifest.xml<?xmlversion="1.0"encoding="utf-8"?><manifestxmlns:android="/apk/res/android"package="mzx.spike.download.app"><uses-permissionandroid:name="android.permission.INTERNET"/><uses-permissionandroid:name="android.permission.WRITE_EXTERNAL_STORAGE"/><applicationandroid:allowBackup="true"android:icon="@drawable/ic_launcher"android:label="@string/app_name"android:theme="@style/AppTheme"><activityandroid:name="mzx.spike.download.app.MainActivity"android:label="@string/app_name"><intent-filter><actionandroid:name="ent.action.MAIN"/><categoryandroid:name="ent.category.LAUNCHER"/></intent-filter></activity></application></manifest>位置:java->package->MainActivity.javapackagemzx.spike.download.app;importandroid.app.Activity;importandroid.app.DownloadManager;importandroid.content.Context;importandroid.content.Intent;importandroid.database.Cursor;import.Uri;importandroid.os.Bundle;importandroid.util.Log;importandroid.view.Menu;importandroid.view.MenuItem;importandroid.view.View;importandroid.widget.Button;importandroid.widget.Toast;importjava.io.IOException;import.MalformedURLException;import.URL;import.URLConnection;publicclassMainActivityextendsActivity{privatestaticfinalStringTAG="Download";@OverrideprotectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);ButtonbuttonDownload=(Button)findViewById(R.id.download_button);buttonDownload.setOnClickListener(newView.OnClickListener(){publicvoidonClick(Viewv){myDownload();}});}@OverridepublicbooleanonCreateOptionsMenu(Menumenu){//Inflatethemenu;thisaddsitemstotheactionbarifitispresent.getMenuInflater().inflate(R.menu.main,menu);returntrue;}@OverridepublicbooleanonOptionsItemSelected(MenuItemitem){//Handleactionbaritemclickshere.Theactionbarwill//automaticallyhandleclicksontheHome/Upbutton,solong//asyouspecifyaparentactivityinAndroidMid=item.getItemId();if(id==R.id.action_settings){returntrue;}returnsuper.onOptionsItemSelected(item);}privatevoidmyDownload(){StringserviceString=Context.DOWNLOAD_SERVICE;DownloadManagerdownloadManager;downloadManager=(DownloadManager)getSystemService(serviceString);Uriuri=Uri.parse("/2014/03/26/TAHITI/TAHITI02.jpg");DownloadManager.Requestrequest=newDownloadManager.Request(uri);request.setDestinationInExternalPublicDir("/Download","file.jpg");request.setVisibleInDownloadsUi(true);longreference=downloadManager.enqueue(request);Log.d(TAG,"DownloadReference:"+reference);Cursorc=downloadManager.query(newDownloadManager.Query().setFilterById(reference));if(c==null){Toast.makeText(this,"Downloadnotfound!",Toast.LENGTH_LONG).show();}else{c.moveToFirst();Log.d(getClass().getName(),"Column_id:"+c.getLong(c.getColumnIndex(DownloadManager.COLUMN_ID)));Log.d(getClass().getName(),"Column_bytes_downloadedsofar:"+c.getLong(c.getColumnIndex(DownloadManager.COLUMN_BYTES_DOWNLOADED_SO_FAR)));Log.d(getClass().getName(),"Columnlastmodifiedtimestamp:"+c.getLong(c.getColumnIndex(DownloadManager.COLUMN_LAST_MODIFIED_TIMESTAMP)));Log.d(getClass().getName(),"Columnlocaluri:"+c.getString(c.getColumnIndex(DownloadManager.COLUMN_LOCAL_URI)));Log.d(getClass().getName(),"Columnstatue:"+c.getInt(c.getColumnIndex(DownloadManager.COLUMN_STATUS)));Log.d(getClass().getName(),"Columnreason:"+c.getInt(c.getColumnIndex(DownloadManager.COLUMN_REASON)));Toast.makeText(this,statusMessage(c),Toast.LENGTH_LONG).show();}startActivity(newIntent(DownloadManager.ACTION_VIEW_DOWNLOADS));}privateStringstatusMessage(Cursorc){switch(c.getInt(c.getColumnIndex(DownloadManager.COLUMN_STATUS))){caseDownloadManager.STATUS_FAILED:return"Downloadfailed";caseDownloadManager.STATUS_PAUSED:return"Downloadpaused";caseDownloadManager.STATUS_PENDING:return"Downloadpending";caseDownloadManager.STATUS_RUNNING:return"Downloadinprogress!";caseDownloadMa