how to detect if is running the scan for new media files on Android (in background)

问题

I have two activity: Main and Processing. in the Processing activity do an edit operation on the file names in a folder, and then start a scan to update via broadcast, and I check when the scan finish.

//end batch renaming operation
//start updating media store library
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED,Uri.parse("file://"+Environment.getExternalStorageDirectory()))); 
//show toast "updating"
op_media_mounted.show();
//catch when updaitng op ends
IntentFilter filter = new IntentFilter(Intent.ACTION_MEDIA_SCANNER_FINISHED);
filter.addDataScheme("file");                   
BroadcastReceiver mReceiver = (new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction().equals(Intent.ACTION_MEDIA_SCANNER_FINISHED)) {
        Toast.makeText(frm_elabora.this, "Scan complete.", Toast.LENGTH_SHORT).show();
                        }
                    }
                });
registerReceiver(mReceiver, filter);

I would like to pass the Activity prevent processing if the scan is running. I can check first if the scan is not running, then launch the second processing activity? as this.

Button btnstart = (Button)findViewById(R.id.btn_start);
btnstart.setOnClickListener(new View.OnClickListener() {
    public void onClick(View view) {
        if ( there_isnt_scan_for_new_media_file )
            startActivity(intent_processing);
        else{
                wait_until_ACTION_MEDIA_SCANNER_FINISHED
                startActivity(intent_processing);
        }

I need to check this, because if i rename the files while android running a scan, when I edit the files in the processing activity, in the end I find other files in the folder with size 0 bytes, as before the change. so I have to wait that the scan finish. i can't find a solution.

UPDATES: i've found this

    public static Uri getMediaScannerUri ()
    Since: API Level 1
    Uri for querying the state of the media scanner.

i try this

    //send broadcast
    sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, 
            Uri.parse("file://" +
            Environment.getExternalStorageDirectory())));
    //show media scanner state
    Toast.makeText(frm_elabora.this,
        MediaStore.getMediaScannerUri().toString(),
        Toast.LENGTH_SHORT).show();

and i get "content://media/none/media_scanner" always... if i ask getMediaScannerUri() after sent ACTION_MEDIA_MOUNTED, i should get something different from "content://media/none/media_scanner" ???

回答1:

did you try MEDIA_SCANNER_VOLUME

Usually when the media scanner is running this column is not null.

来源：https://stackoverflow.com/questions/9647478/how-to-detect-if-is-running-the-scan-for-new-media-files-on-android-in-backgrou

标签

android

background

detect

mediastore