android 获取视频,图片缩略图的具体实现

1、获取视频缩略图有两个方法(1)通过内容提供器来获取(2)人为创建缩略图

(1)缺点就是必须更新媒体库才能看到最新的视频的缩略图

[java]

/**
     * @param context
     * @param cr
     * @param videopath
     * @return
     */
    public static bitmap getvideothumbnail(context context, contentresolver cr, string videopath) { 
            contentresolver testcr = context.getcontentresolver(); 
            string[] projection = { mediastore.video.media.data, mediastore.video.media._id, }; 
            string whereclause = mediastore.video.media.data + " = '" + videopath + "'"; 
            cursor cursor = testcr.query(mediastore.video.media.external_content_uri, projection, whereclause, 
                            null, null); 
            int _id = 0; 
            string videopath = ""; 
            if (cursor == null || cursor.getcount() == 0) { 
                    return null; 
            } 
            if (cursor.movetofirst()) { 

                    int _idcolumn = cursor.getcolumnindex(mediastore.video.media._id); 
                    int _datacolumn = cursor.getcolumnindex(mediastore.video.media.data); 
                    do { 
                            _id = cursor.getint(_idcolumn); 
                            videopath = cursor.getstring(_datacolumn); 
                    } while (cursor.movetonext()); 
            } 
            cursor.close();
            bitmapfactory.options options = new bitmapfactory.options(); 
            options.indither = false; 
            options.inpreferredconfig = bitmap.config.rgb_565; 
            bitmap bitmap = mediastore.video.thumbnails.getthumbnail(cr, _id, images.thumbnails.mini_kind, 
                            options); 
            return bitmap; 
    }

/**
     * @param context
     * @param cr
     * @param videopath
     * @return
     */
    public static bitmap getvideothumbnail(context context, contentresolver cr, string videopath) {
            contentresolver testcr = context.getcontentresolver();
            string[] projection = { mediastore.video.media.data, mediastore.video.media._id, };
            string whereclause = mediastore.video.media.data + " = '" + videopath + "'";
            cursor cursor = testcr.query(mediastore.video.media.external_content_uri, projection, whereclause,
                            null, null);
            int _id = 0;
            string videopath = "";
            if (cursor == null || cursor.getcount() == 0) {
                    return null;
            }
            if (cursor.movetofirst()) {

                    int _idcolumn = cursor.getcolumnindex(mediastore.video.media._id);
                    int _datacolumn = cursor.getcolumnindex(mediastore.video.media.data);
                    do {
                            _id = cursor.getint(_idcolumn);
                            videopath = cursor.getstring(_datacolumn);
                    } while (cursor.movetonext());
            }
            cursor.close();
            bitmapfactory.options options = new bitmapfactory.options();
            options.indither = false;
            options.inpreferredconfig = bitmap.config.rgb_565;
            bitmap bitmap = mediastore.video.thumbnails.getthumbnail(cr, _id, images.thumbnails.mini_kind,
                            options);
            return bitmap;
    }(2)人为创建缩略图要耗费一点时间

[java]

/**
    * 获取视频缩略图
    * @param videopath
    * @param width
    * @param height
    * @param kind
    * @return
    */
   private bitmap getvideothumbnail(string videopath, int width , int height, int kind){
    bitmap bitmap = null;
    bitmap = thumbnailutils.createvideothumbnail(videopath, kind);
    bitmap = thumbnailutils.extractthumbnail(bitmap, width, height, thumbnailutils.options_recycle_input);
    return bitmap;
   }

 /**
     * 获取视频缩略图
     * @param videopath
     * @param width
     * @param height
     * @param kind
     * @return
     */
    private bitmap getvideothumbnail(string videopath, int width , int height, int kind){
  bitmap bitmap = null;
  bitmap = thumbnailutils.createvideothumbnail(videopath, kind);
  bitmap = thumbnailutils.extractthumbnail(bitmap, width, height, thumbnailutils.options_recycle_input);
  return bitmap;
    }

2、图片缩略图

[java]

/**
    * 
    * @param context
    * @param cr
    * @param imagepath
    * @return
    */
   public static bitmap getimagethumbnail(context context, contentresolver cr, string imagepath) { 
           contentresolver testcr = context.getcontentresolver(); 
           string[] projection = { mediastore.images.media.data, mediastore.images.media._id, }; 
           string whereclause = mediastore.images.media.data + " = '" + imagepath + "'"; 
           cursor cursor = testcr.query(mediastore.images.media.external_content_uri, projection, whereclause, 
                           null, null); 
           int _id = 0; 
           string imagepath = ""; 
           if (cursor == null || cursor.getcount() == 0) { 
                   return null; 
           } 
           if (cursor.movetofirst()) { 

                   int _idcolumn = cursor.getcolumnindex(mediastore.images.media._id); 
                   int _datacolumn = cursor.getcolumnindex(mediastore.images.media.data); 

                   do { 
                           _id = cursor.getint(_idcolumn); 
                           imagepath = cursor.getstring(_datacolumn); 
                   } while (cursor.movetonext()); 
           } 
           cursor.close();
           bitmapfactory.options options = new bitmapfactory.options(); 
           options.indither = false; 
           options.inpreferredconfig = bitmap.config.rgb_565; 
           bitmap bitmap = mediastore.images.thumbnails.getthumbnail(cr, _id, images.thumbnails.mini_kind, 
                           options); 
           return bitmap; 
   }

 /**
     *
     * @param context
     * @param cr
     * @param imagepath
     * @return
     */
    public static bitmap getimagethumbnail(context context, contentresolver cr, string imagepath) {
            contentresolver testcr = context.getcontentresolver();
            string[] projection = { mediastore.images.media.data, mediastore.images.media._id, };
            string whereclause = mediastore.images.media.data + " = '" + imagepath + "'";
            cursor cursor = testcr.query(mediastore.images.media.external_content_uri, projection, whereclause,
                            null, null);
            int _id = 0;
            string imagepath = "";
            if (cursor == null || cursor.getcount() == 0) {
                    return null;
            }
            if (cursor.movetofirst()) {

                    int _idcolumn = cursor.getcolumnindex(mediastore.images.media._id);
                    int _datacolumn = cursor.getcolumnindex(mediastore.images.media.data);

                    do {
                            _id = cursor.getint(_idcolumn);
                            imagepath = cursor.getstring(_datacolumn);
                    } while (cursor.movetonext());
            }
            cursor.close();
            bitmapfactory.options options = new bitmapfactory.options();
            options.indither = false;
            options.inpreferredconfig = bitmap.config.rgb_565;
            bitmap bitmap = mediastore.images.thumbnails.getthumbnail(cr, _id, images.thumbnails.mini_kind,
                            options);
            return bitmap;
    }