How to Enable Android Download Manager

问题

I'm using Android Download Manager to download list of files. Lately I came across a crash report saying

Unknown java.lang.IllegalArgumentException: Unknown URL content://downloads/my_downloads

Then later, I figured it out that the reason is because user disabled Android Download Manager. I check if the Download Manager is disabled by checking it's package name with the code below.

int state = this.getPackageManager().getApplicationEnabledSetting("com.android.providers.downloads");

And now, I need to find a way to enable the Download Manager if it is disabled. I tried setting it's enable state with the permission in Manifest but I keep getting Security Exception.

this.getPackageManager().setApplicationEnabledSetting("com.android.providers.downloads", PackageManager.COMPONENT_ENABLED_STATE_DEFAULT, 0);

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

So I thought it might not be reachable because of it is a system app. (Google Play App does it).

Is there any way to redirect the user to the Download Manager Application Info view ? to let the user enables it ? If there is no way to enable it on run time programmatically.

回答1:

Please edit my answer if is not valid

Check if download manager is available:

   int state = this.getPackageManager().getApplicationEnabledSetting("com.android.providers.downloads");

if(state==PackageManager.COMPONENT_ENABLED_STATE_DISABLED||
state==PackageManager.COMPONENT_ENABLED_STATE_DISABLED_USER
||state==PackageManager.COMPONENT_ENABLED_STATE_DISABLED_UNTIL_USED){

// Cannot download using download manager
}

            else {
                request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, fileName);
                request.setDescription(fileName);   
                manager.enqueue(request); 
            }

And the solution for trying to enable download manager is:

packageName = "com.android.providers.downloads"

try {
    //Open the specific App Info page:
    Intent intent = new Intent(android.provider.Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
    intent.setData(Uri.parse("package:" + packageName));
    startActivity(intent);

} catch ( ActivityNotFoundException e ) {
    //e.printStackTrace();

    //Open the generic Apps page:
    Intent intent = new Intent(android.provider.Settings.ACTION_MANAGE_APPLICATIONS_SETTINGS);
    startActivity(intent);

}

回答2:

Some folks were looking for an answer to this question and I just realized that the Answer made to this question is somehow deleted. So I want to answer my own question.

There is no way to activate/deactivate Download Manager directly, since it's system application and we don't have access to it.

Only alternative left is to redirect the User to the Info Page of Download Manager Application.

try {
     //Open the specific App Info page:
     Intent intent = new Intent(android.provider.Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
     intent.setData(Uri.parse("package:" + "com.android.providers.downloads"));
     startActivity(intent);

} catch ( ActivityNotFoundException e ) {
     e.printStackTrace();

     //Open the generic Apps page:
     Intent intent = new Intent(android.provider.Settings.ACTION_MANAGE_APPLICATIONS_SETTINGS);
     startActivity(intent);
}

回答3:

Google Gmail Inbox has check whether the DownloadManager is been disabled,if true then show an AlertDialog to tell user to enable the DownloadManager in Settings.The screenshot show below:

I wrote a class called DownloadManagerResolver to fix this,hope this can help your.:)

public final class DownloadManagerResolver {

private static final String DOWNLOAD_MANAGER_PACKAGE_NAME = "com.android.providers.downloads";

/**
 * Resolve whether the DownloadManager is enable in current devices.
 *
 * @return true if DownloadManager is enable,false otherwise.
 */
public static boolean resolve(Context context) {
    boolean enable = resolveEnable(context);
    if (!enable) {
        AlertDialog alertDialog = createDialog(context);
        alertDialog.show();
    }
    return enable;
}

/**
 * Resolve whether the DownloadManager is enable in current devices.
 *
 * @param context
 * @return true if DownloadManager is enable,false otherwise.
 */
private static boolean resolveEnable(Context context) {
    int state = context.getPackageManager()
            .getApplicationEnabledSetting(DOWNLOAD_MANAGER_PACKAGE_NAME);

    if (Build.VERSION.SDK_INT > Build.VERSION_CODES.JELLY_BEAN_MR2) {
        return !(state == PackageManager.COMPONENT_ENABLED_STATE_DISABLED ||
                state == PackageManager.COMPONENT_ENABLED_STATE_DISABLED_USER
                || state == PackageManager.COMPONENT_ENABLED_STATE_DISABLED_UNTIL_USED);
    } else {
        return !(state == PackageManager.COMPONENT_ENABLED_STATE_DISABLED ||
                state == PackageManager.COMPONENT_ENABLED_STATE_DISABLED_USER);
    }
}

private static AlertDialog createDialog(final Context context) {
    AppCompatTextView messageTextView = new AppCompatTextView(context);
    messageTextView.setTextSize(16f);
    messageTextView.setText("DownloadManager is disabled. Please enable it.");
    return new AlertDialog.Builder(context)
            .setView(messageTextView, 50, 30, 50, 30)
            .setPositiveButton("ok", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    enableDownloadManager(context);
                }
            })
            .setCancelable(false)
            .create();
}

/**
 * Start activity to Settings to enable DownloadManager.
 */
private static void enableDownloadManager(Context context) {
    try {
        //Open the specific App Info page:
        Intent intent = new Intent(android.provider.Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
        intent.setData(Uri.parse("package:" + DOWNLOAD_MANAGER_PACKAGE_NAME));
        context.startActivity(intent);
    } catch (ActivityNotFoundException e) {
        e.printStackTrace();

        //Open the generic Apps page:
        Intent intent = new Intent(android.provider.Settings.ACTION_MANAGE_APPLICATIONS_SETTINGS);
        context.startActivity(intent);
    }
}
}

回答4:

May be it's help to you.

downloadManager = (DownloadManager)getSystemService(DOWNLOAD_SERVICE);
   DownloadManager.Request request = new DownloadManager.Request(Download_Uri);
   //Restrict the types of networks over which this download may proceed.
   request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI | DownloadManager.Request.NETWORK_MOBILE);
   //Set whether this download may proceed over a roaming connection.
   request.setAllowedOverRoaming(false);
   //Set the title of this download, to be displayed in notifications (if enabled).
   request.setTitle("My Data Download");
   //Set a description of this download, to be displayed in notifications (if enabled)
   request.setDescription("Android Data download using DownloadManager.");
   //Set the local destination for the downloaded file to a path within the application's external files directory
   request.setDestinationInExternalFilesDir(this,Environment.DIRECTORY_DOWNLOADS,"CountryList.json");

   //Enqueue a new download and same the referenceId
   downloadReference = downloadManager.enqueue(request);

http://www.mysamplecode.com/2012/09/android-downloadmanager-example.html

来源：https://stackoverflow.com/questions/21551538/how-to-enable-android-download-manager