Android Q：通过MediaStore获取包含位置信息的图库

Question

查看Android Q here中引入的存储访问更改，现在默认情况下会修改位置信息。

Google要求我们在媒体的uri作为参数的“MediaStore”对象上调用setRequireOriginal()。当您逐个获取媒体时，这是有效的，但是当我们在整个图库中查询ContentResolver时呢？

看这个样本：

String[] projection = {
        MediaStore.Files.FileColumns._ID,
        MediaStore.Files.FileColumns.DATA,
        MediaStore.Files.FileColumns.MEDIA_TYPE,
        MediaStore.Images.Media.DATE_TAKEN,
        MediaStore.Images.Media.WIDTH,
        MediaStore.Images.Media.HEIGHT,
        MediaStore.Images.Media.LATITUDE, // <----- THIS
        MediaStore.Images.Media.LONGITUDE, // <----- THIS
        MediaStore.Images.Media.MIME_TYPE,
};

String selection = MediaStore.Files.FileColumns.MEDIA_TYPE + "="
        + MediaStore.Files.FileColumns.MEDIA_TYPE_IMAGE;

Uri queryUri = MediaStore.Files.getContentUri("external");

Cursor cursor = null;
MediaStore a ;

try {
    cursor = context.getContentResolver().query(queryUri, projection, selection,
            null, MediaStore.Images.Media.DATE_TAKEN + " DESC");


}
catch (NullPointerException ex){
}

从Q开始，纬度和经度始终设置为0.假设在Manifest中添加了ACCESS_MEDIA_LOCATION权限，是否有办法获取一批媒体的位置数据？

Answer 1

不幸的是，MediaStore.Images.Media.LATITUDE和MediaStore.Images.Media.LONGITUDE是deprecated in Android Q。

The work around这是使用这样的ExifInterface：

Cursor cursor = null;
try {
    String[] projection = {
            MediaStore.Files.FileColumns._ID,
            MediaStore.Images.Media.DATE_TAKEN,
            MediaStore.Images.Media.WIDTH,
            MediaStore.Images.Media.HEIGHT,
            MediaStore.MediaColumns.TITLE,
            MediaStore.Images.Media.MIME_TYPE,
            MediaStore.Images.Media.LATITUDE,
            MediaStore.Images.Media.LONGITUDE
    };
    cursor = getContentResolver().query(
            MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
            projection,
            null,
            null,
            MediaStore.Images.Media.DATE_TAKEN + " DESC");


    int idColumn = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns._ID);
    int titleColumn = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.TITLE);
    int latColumn = BuildCompat.isAtLeastQ() ? -1
            : cursor.getColumnIndexOrThrow(MediaStore.Images.Media.LATITUDE);
    int longColumn = BuildCompat.isAtLeastQ() ? -1
            : cursor.getColumnIndexOrThrow(MediaStore.Images.Media.LONGITUDE);
    while (cursor.moveToNext()) {

        Uri photoUri = Uri.withAppendedPath(
                MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                cursor.getString(idColumn));
        String title = cursor.getString(titleColumn);

        final double[] latLong;
        if (BuildCompat.isAtLeastQ()) {
            photoUri = MediaStore.setRequireOriginal(photoUri);
            InputStream stream = getContentResolver().openInputStream(photoUri);
            if (stream == null) {
                Log.w(TAG, "Got a null input stream for " + photoUri);
                continue;
            }

            ExifInterface exifInterface = new ExifInterface(stream);
            double[] returnedLatLong = exifInterface.getLatLong();
            // If it returns null, fall back to {0.0, 0.0}.
            latLong = returnedLatLong != null ? returnedLatLong : new double[2];

            // After using ExifInterface, the stream should not be reused.
            stream.close();
        } else {
            latLong = new double[]{
                    cursor.getFloat(latColumn),
                    cursor.getFloat(longColumn)
            };
        }

        Log.i(TAG, title + " | lat: " + latLong[0] + " | lng: " + latLong[1]);
    }
} catch (NullPointerException | IOException ex) {
    Log.e(TAG, "Caught exception", ex);
} finally {
    if (cursor != null) {
        cursor.close();
    }
}

这是目前在Android Q上获取照片的纬度和经度的唯一方法。

这需要持有ACCESS_MEDIA_LOCATION许可。