Access ordered images and video in same Cursor

问题

I'm using the android.content.CursorLoader class to create two Cursor objects to access media stored on the user of my app's device. I'd like to give the user a grid view of their stored images and video which preserves order from the Android Gallery app.

Currently I'm using one Cursor to access Images and one to access Video. With this approach, all images precede all videos (i.e. they are in two separate groups). Is there a way to access both Images and Video from the same Cursor? If not, is there a better way to access these media on the device?

For reference, here is the code I am using:

For Images:

CursorLoader cursorLoader = new CursorLoader(
    mContext,
    MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
    IMAGE_PROJECTION,
    null,
    null,
    MediaStore.Images.Media._ID + " desc"
  );
  mImageCursor = cursorLoader.loadInBackground();

And Video:

CursorLoader cursorLoader = new CursorLoader(
    mContext,
    MediaStore.Video.Media.EXTERNAL_CONTENT_URI,
    VIDEO_PROJECTION,
    null,
    null,
    MediaStore.Video.Media._ID + " desc"
  );
  mVideoCursor = cursorLoader.loadInBackground();

回答1:

After lots of research and playing around with source code, I'm finally a bit more familiar with the Android filesystem. To get a single Cursor which can access information about both Images and Video I used the following:

// Get relevant columns for use later.
String[] projection = {
    MediaStore.Files.FileColumns._ID, 
    MediaStore.Files.FileColumns.DATA,
    MediaStore.Files.FileColumns.DATE_ADDED,
    MediaStore.Files.FileColumns.MEDIA_TYPE,
    MediaStore.Files.FileColumns.MIME_TYPE,
    MediaStore.Files.FileColumns.TITLE
};

// Return only video and image metadata.
String selection = MediaStore.Files.FileColumns.MEDIA_TYPE + "="
         + MediaStore.Files.FileColumns.MEDIA_TYPE_IMAGE 
         + " OR "
         + MediaStore.Files.FileColumns.MEDIA_TYPE + "="
         + MediaStore.Files.FileColumns.MEDIA_TYPE_VIDEO;

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

CursorLoader cursorLoader = new CursorLoader(
    this,
    queryUri,
    projection,
    selection,
    null, // Selection args (none).
    MediaStore.Files.FileColumns.DATE_ADDED + " DESC" // Sort order.
  );

Cursor cursor = cursorLoader.loadInBackground();

来源：https://stackoverflow.com/questions/17664826/access-ordered-images-and-video-in-same-cursor

标签

android

image

video

cursor

media