Android系统启动时会去扫描系统文件，并将系统支持的视频文件（mp4,3gp,wmv）扫描到媒体库（MediaStore）中，下面代码演示如何获得这些文件的信息：

publicstatic List<VideoInfo> sysVideoList = null;// 视频信息集合 
sysVideoList = new ArrayList<VideoInfo>();   
setVideoList();

privatevoid setVideoList() {   
// MediaStore.Video.Thumbnails.DATA:视频缩略图的文件路径 
        String[] thumbColumns = { MediaStore.Video.Thumbnails.DATA,   
                MediaStore.Video.Thumbnails.VIDEO_ID };

// MediaStore.Video.Media.DATA：视频文件路径； 
// MediaStore.Video.Media.DISPLAY_NAME : 视频文件名，如 testVideo.mp4 
// MediaStore.Video.Media.TITLE: 视频标题 : testVideo 
        String[] mediaColumns = { MediaStore.Video.Media._ID,   
                MediaStore.Video.Media.DATA, MediaStore.Video.Media.TITLE,   
                MediaStore.Video.Media.MIME_TYPE,   
                MediaStore.Video.Media.DISPLAY_NAME };

cursor = managedQuery(MediaStore.Video.Media.EXTERNAL_CONTENT_URI,   
                mediaColumns, null, null, null);

if(cursor==null){   
            Toast.makeText(SystemVideoChooseActivity.this, "没有找到可播放视频文件", 1).show();   
return;   
        }   
if (cursor.moveToFirst()) {   
do {   
                VideoInfo info = new VideoInfo();   
int id = cursor.getInt(cursor   
                        .getColumnIndex(MediaStore.Video.Media._ID));   
                Cursor thumbCursor = managedQuery(   
                        MediaStore.Video.Thumbnails.EXTERNAL_CONTENT_URI,   
                        thumbColumns, MediaStore.Video.Thumbnails.VIDEO_ID   
                                + "=" + id, null, null);   
if (thumbCursor.moveToFirst()) {   
                    info.setThumbPath(thumbCursor.getString(thumbCursor   
                            .getColumnIndex(MediaStore.Video.Thumbnails.DATA)));   
                }   
                info.setPath(cursor.getString(cursor   
                        .getColumnIndexOrThrow(MediaStore.Video.Media.DATA)));   
                info.setTitle(cursor.getString(cursor   
                        .getColumnIndexOrThrow(MediaStore.Video.Media.TITLE)));

info.setDisplayName(cursor.getString(cursor   
                        .getColumnIndexOrThrow(MediaStore.Video.Media.DISPLAY_NAME)));  
                LogUtil.log(TAG, "DisplayName:"+info.getDisplayName());   
                info.setMimeType(cursor   
                        .getString(cursor   
                                .getColumnIndexOrThrow(MediaStore.Video.Media.MIME_TYPE)));

sysVideoList.add(info);   
            } while (cursor.moveToNext());   
        }   
    }

　　有一点需要注意的是：系统的媒体库并不会在我们添加视频文件后自动更新，我们如何去手动扫描媒体库，或者重启系统才能从媒体库中得到更新的视频文件：

　　sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://"

　　+ Environment.getExternalStorageDirectory())));