如何使用下載管理器在Android的

Question

如何使用下載管理器

代碼保存在內部存儲的圖像或MP3文件存儲下載的圖像在內部存儲文件在我的內部存儲 但它不能很好地工作 所需的路徑是「數據/數據/包/ app_channel1/image1.jpg」

Answer 1

只有你自己的應用程序可以Access到App internal storage默認android內置下載管理器無法訪問您的應用程序內部存儲器，因此您不能在內部存儲器中下載。

解決方案：

下載文件中sd card臨時文件，當下載完成register a receive，然後從external複製文件到internal storage.

完整代碼：

public class MainActivity extends Activity { 
    private long enqueue; 
    private DownloadManager dm; 

    /** 
    * Called when the activity is first created. 
    */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     BroadcastReceiver receiver = new BroadcastReceiver() { 
      @Override 
      public void onReceive(Context context, Intent intent) { 
       String action = intent.getAction(); 
       if (DownloadManager.ACTION_DOWNLOAD_COMPLETE.equals(action)) { 
        long downloadId = intent.getLongExtra(
          DownloadManager.EXTRA_DOWNLOAD_ID, 0); 
        DownloadManager.Query query = new DownloadManager.Query(); 
        query.setFilterById(enqueue); 
        Cursor c = dm.query(query); 
        if (c.moveToFirst()) { 
         int columnIndex = c 
           .getColumnIndex(DownloadManager.COLUMN_STATUS); 
         if (DownloadManager.STATUS_SUCCESSFUL == c 
           .getInt(columnIndex)) { 

          ImageView view = (ImageView) findViewById(R.id.imageView1); 
          String uriString = c 
            .getString(c 
              .getColumnIndex(DownloadManager.COLUMN_LOCAL_URI)); 

          Uri a = Uri.parse(uriString); 
          File d = new File(a.getPath()); 
          // copy file from external to internal will esaily avalible on net use google. 
          view.setImageURI(a); 
         } 
        } 
       } 
      } 
     }; 

     registerReceiver(receiver, new IntentFilter(
       DownloadManager.ACTION_DOWNLOAD_COMPLETE)); 
    } 

    public void onClick(View view) { 
     dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE); 
     DownloadManager.Request request = new DownloadManager.Request(
       Uri.parse("http://www.vogella.de/img/lars/LarsVogelArticle7.png")).setDestinationInExternalPublicDir("/Sohail_Temp", "test.jpg"); 
     enqueue = dm.enqueue(request); 
    } 

    public void showDownload(View view) { 
     Intent i = new Intent(); 
     i.setAction(DownloadManager.ACTION_VIEW_DOWNLOADS); 
     startActivity(i); 
    } 
} 

佈局：

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:orientation="vertical"> 

    <Button 
     android:id="@+id/button1" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:onClick="onClick" 
     android:text="Start Download"></Button> 

    <Button 
     android:id="@+id/button2" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:onClick="showDownload" 
     android:text="View Downloads"></Button> 

    <ImageView 
     android:id="@+id/imageView1" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:src="@drawable/image_1"></ImageView> 
</LinearLayout> 

權限：

<uses-permission android:name="android.permission.INTERNET" /> 
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />