MediaProvider
MediaProvider就是Android系统中的一个数据库，又称多媒体数据库，保存了手机上存储的所有文件的信息。类似的还有TelephonyProvider、CalendarProvider、ContactsProvider。
这个数据库存放在/data/data/com.android.providers.media/databases当中，里面有两个数据库：internal.db和external.db，internal.db存放的是系统分区的文件信息，开发者是没法通过接口获得其中的信息的，而external.db存放的则是我们用户能看到的存储区的文件信息，即包含了手机内置存储，还包含了SD卡。
如果你的手机root了，可以使用SQLite Expert 这个软件查看其中的内容。
MediaStore
public final class MediaStore
extends Object
MediaProvider提供了在内部和外部存储设备上所有可用媒体的元数据。
内嵌类
class MediaStore.Audio
所有音频内容的容器class MediaStore.Files
MediaProvider表包含媒体存储中所有文件的索引，包括非媒体文件class MediaStore.Images
所有图片内容的容器interface MediaStore.MediaColumns
MediaProvider表的公共字段class MediaStore.Video
所有视频内容的容器
MediaStore.MediaColumns字段说明
String DATA
磁盘上文件的路径String DATE_ADDED
文件添加到media provider的时间（单位秒）String DATE_MODIFIED
文件最后一次修改单元的时间String DISPLAY_NAME
文件的显示名称String HEIGHT
图像/视频的高度，以像素为单位String MIME_TYPE
文件的MIME类型String SIZE
文件的字节大小String TITLE
标题String WIDTH
图像/视频的宽度，以像素为单位。
DEMO
通过MediaProvider读取多媒体数据库中的视频、图片和音频，并显示在RecyclerView中。
- 读取视频
/**
* 获取视频列表
*/
public List getVideoList() {
List list = new ArrayList();
ContentResolver contentResolver = context.getContentResolver();
Uri uri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
String[] projection = null;
String selection = null;
//MediaStore.Video.Media.MIME_TYPE + "=? or " + MediaStore.Video.Media.MIME_TYPE + "=?";
String[] selectionArgs = null;
//new String[]{"video/mp4", "video/avi"};
String sortOrder = null;
//MediaStore.Video.Media.DEFAULT_SORT_ORDER;
Cursor cursor = contentResolver.query(uri, projection, selection, selectionArgs, sortOrder);
Cursor thumbCursor = null;
while (cursor.moveToNext()) {
MediaInfo videoInfo = new VideoInfo();
videoInfo.id = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Video.Media._ID));
videoInfo.filePath = cursor.getString(cursor.getColumnIndex(MediaStore.Video.Media.DATA));
videoInfo.mimeType= cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Video.Media.MIME_TYPE));
videoInfo.title= cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Video.Media.TITLE));
videoInfo.addTime=cursor.getLong(cursor.getColumnIndex(MediaStore.Video.Media.DATE_ADDED));
((VideoInfo) videoInfo).duration=cursor.getLong(cursor.getColumnIndex(MediaStore.Video.Media.DURATION));
thumbCursor = contentResolver.query(MediaStore.Video.Thumbnails.EXTERNAL_CONTENT_URI,
new String[]{
MediaStore.Video.Thumbnails.DATA,
MediaStore.Video.Thumbnails.VIDEO_ID
},
MediaStore.Video.Thumbnails.VIDEO_ID + "=?",
new String[]{String.valueOf(videoInfo.id)}, null);
if (thumbCursor.moveToFirst()) {
((VideoInfo) videoInfo).thumbnail = thumbCursor.getString(
thumbCursor.getColumnIndexOrThrow(MediaStore.Video.Thumbnails.DATA));
}
list.add(videoInfo);
}
thumbCursor.close();
cursor.close();
return list;
}
- 读取图片
public List getImageList() {
List list = new ArrayList();
ContentResolver contentResolver = context.getContentResolver();
Uri uri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
String[] projection = null;
String selection = null;
String[] selectionArgs = null;
String sortOrder = null;
Cursor cursor = contentResolver.query(uri, projection, selection, selectionArgs, sortOrder);
Cursor thumbCursor = null;
while (cursor.moveToNext()) {
MediaInfo imageInfo = new ImageInfo();
imageInfo.id = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Images.Media._ID));
imageInfo.filePath = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
imageInfo.mimeType= cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.MIME_TYPE));
imageInfo.title= cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.TITLE));
imageInfo.addTime=cursor.getLong(cursor.getColumnIndex(MediaStore.Images.Media.DATE_ADDED));
thumbCursor = contentResolver.query(MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI,
new String[]{
MediaStore.Images.Thumbnails.DATA,
MediaStore.Images.Thumbnails.IMAGE_ID
},
MediaStore.Images.Thumbnails.IMAGE_ID + "=?",
new String[]{String.valueOf(imageInfo.id)}, null);
if (thumbCursor.moveToFirst()) {
((ImageInfo) imageInfo).thumbnail = thumbCursor.getString(
thumbCursor.getColumnIndexOrThrow(MediaStore.Images.Thumbnails.DATA));
}
list.add(imageInfo);
}
thumbCursor.close();
cursor.close();
return list;
}
- 读取音频
public List getAudioList() {
List list = new ArrayList();
ContentResolver contentResolver = context.getContentResolver();
Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
String[] projection = null;
String selection = null;
String[] selectionArgs = null;
String sortOrder = null;
Cursor cursor = contentResolver.query(uri, projection, selection, selectionArgs, sortOrder);
while (cursor.moveToNext()) {
MediaInfo audioInfo = new AudioInfo();
audioInfo.id = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media._ID));
audioInfo.filePath = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DATA));
audioInfo.mimeType= cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.MIME_TYPE));
audioInfo.title= cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.TITLE));
audioInfo.addTime=cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.DATE_ADDED));
list.add(audioInfo);
}
cursor.close();
return list;
}
代码
https://github.com/DavidJi80/Android
v0.5
参考
https://blog.csdn.net/qugename/article/details/53230857
https://developer.android.google.cn/reference/android/provider/MediaStore
https://blog.csdn.net/wbwjx/article/details/70544881
https://blog.csdn.net/mba16c35/article/details/43528389
https://www.cnblogs.com/ldq2016/p/5584971.html