Android获取SD卡上图片和视频的缩略图

如果我们需要快速提取图片和视频缩略图可以直接访问 android.provider.MediaStore.Images.Thumbnails 和android.provider.MediaStore.Video.Thumbnails这两个数据库，即可查询出来缩略图 。

如何判断文件呢? 可以通过Cursor遍历数据库，对比INTERNAL_CONTENT_URI字段的值，这是一个Uri，这里保存着Android手机SD卡上的多媒体文件完整路径。

[java] view plaincopyprint?

1. Uri originalUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
2. //若为视频则为MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
3. ContentResolver cr = this.getContentResolver();
4. Cursor cursor = cr.query(originalUri, null,null, null,null);
5. if (cursor == null) {
6. return;
7. }
8. for (cursor.moveToFirst();!cursor.isAfterLast(); cursor.moveToNext()) {
9. long thumbNailsId = cursor.getLong(cursor .getColumnIndex("_ID"));
10. Bitmap bitmap = MediaStore.Images.Thumbnails.getThumbnail(cr,
11. thumbNailsId, Video.Thumbnails.MICRO_KIND, null);
12. //若为视频则为
13. // Bitmap bitmap = MediaStore.Video.Thumbnails.getThumbnail(cr,
14. // thumbNailsId, Video.Thumbnails.MICRO_KIND, null);
15. return bitmap;
16. }

Uri originalUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;//若为视频则为MediaStore.Video.Media.EXTERNAL_CONTENT_URI;ContentResolver cr = this.getContentResolver();Cursor cursor = cr.query(originalUri, null, null, null, null);if (cursor == null) {return;}for (cursor.moveToFirst();!cursor.isAfterLast(); cursor.moveToNext()) {long thumbNailsId = cursor.getLong(cursor.getColumnIndex("_ID"));Bitmap bitmap = MediaStore.Images.Thumbnails.getThumbnail(cr,thumbNailsId, Video.Thumbnails.MICRO_KIND, null);//若为视频则为//Bitmap bitmap = MediaStore.Video.Thumbnails.getThumbnail(cr,//thumbNailsId, Video.Thumbnails.MICRO_KIND, null);return bitmap;}