I recently upgraded the app's target version to API 29. Due to the scoped storage in Android 10, i used MediaStore API to store and retrieve images from app external storage. Earlier, i used getExternalStoragePublicDirectory
to store images taken through camera, now i use MediaStore.Images.Media.EXTERNAL_CONTENT_URI
to write file to an external storage location.
Issue i am facing now is, When i open my app and take pictures, it stores under a folder name that i gave 'myapp' and i can retrieve my images through Mediastore cursor and show them in a custom gallery. And when i uninstall my app 'myapp' folder still exists. And when i install my app again and try to read the images from the gallery, cursor is not returning any image. But if i take picture again, then i could load them to my custom gallery. Custom gallery view is just a row of images at the bottom of the screen, so that user doesn't have to browse through the photos folder to load the image to the app.
This is how i store my images in the MediaStore
Content values:
String RELATIVE_PATH = Environment.DIRECTORY_PICTURES + File.separator + "myApp";
final ContentValues contentValues = new ContentValues();
contentValues.put(MediaStore.MediaColumns.DISPLAY_NAME, generateImageName(new Date()));
contentValues.put(MediaStore.MediaColumns.MIME_TYPE, "image/jpg");
contentValues.put(MediaStore.MediaColumns.RELATIVE_PATH, RELATIVE_PATH);
Generate Name method:
int sameSecondCount;
protected String generateName(Date now)
{
String result = formatter.format(now);
long nowMillis = now.getTime();
if (nowMillis / 1000 == lastMillis / 1000)
{
sameSecondCount++;
result += "_" + sameSecondCount;
}
else
sameSecondCount = 0;
lastMillis = nowMillis;
return result + PICTURE_EXTENSION_JPG;
}
@WorkerThread
private Uri writePictureToFile(ContentValues contentValues, byte[] bitmapBytes) throws IOException
{
final ContentResolver resolver = getApplication().getContentResolver();
Uri uri = null;
final Uri contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
try
{
uri = resolver.insert(contentUri, contentValues);
if (uri == null)
throw new IOException("Failed to create new MediaStore record.");
OutputStream stream = resolver.openOutputStream(uri);
if (stream == null)
{
throw new IOException("Failed to get output stream.");
}
stream.write(bitmapBytes);
}
catch (IOException e)
{
// Delete the content from the media store
if (uri != null)
resolver.delete(uri, null, null);
throw e;
}
return uri;
}
Reading images
{
String selectionMimeType = MediaStore.Files.FileColumns.MIME_TYPE + " in (?,?,?)";
String[] args = new String[]{
MimeTypeMap.getSingleton().getMimeTypeFromExtension("jpg"),
MimeTypeMap.getSingleton().getMimeTypeFromExtension("png")};
Cursor cursor = context.getContentResolver()
.query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, columns, selectionMimeType, selectionArgs,
orderBy + " DESC");
if (cursor != null)
{
int idColumnIndex = imageCursor.getColumnIndex(MediaStore.Images.Media._ID);
imageCursor.moveToFirst();
int imageCount = imageCursor.getCount();
for (int i = 0; i < imageCount && i < totalCount; i++)
{
final long imageId = imageCursor.getLong(idColumnIndex);
Uri uriImage = Uri.withAppendedPath(uriExternal, "" + imageId);
GalleryData galleryImageData = new GalleryImageData(imageId, uriImage); // Custom class with id and Uri
galleryViewModelList.add(galleryImageData);
imageCursor.moveToNext();
}
imageCursor.close();
}
Why the images that i stored in the folder in Mediastore is not being returned by the above code when i reinstall my App. Is it by design or am i missing something?
These are the columns i am retrieving,
final String[] columns = { MediaStore.Images.Media.DATA, MediaStore.Images.Media._ID, MediaStore.Images.Media.MIME_TYPE };
final String orderBy = MediaStore.Images.Media.DATE_TAKEN; ```
RELATIVE_PATH);
? What is RELATIVE_PATH ? Should we guess? And why dont you put that at the start of your post? Write a decent post. – GimbleREAD_EXTERNAL_STORAGE
. – Idel