android获取图片和视频的缩略图
获取图片缩略图：
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byte[] imageByte=getImageFromURL(urlPath.trim()); //以下是把图片转化为缩略图再加载BitmapFactory.Options options = new BitmapFactory.Options(); options.inJustDecodeBounds = true;BitmapFactory.decodeByteArray(imageByte, 0, imageByte.length,options ); ?//此时返回bitmap为空?
options.inJustDecodeBounds = false;int be = (int)(options.outHeight / (float)200); if (be <= 0){ be = 1; } options.inSampleSize = be; return BitmapFactory.decodeByteArray(imageByte, 0, imageByte.length,options); //返回缩略图?
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获取视频缩略图：
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/**
* 根据视频Uri地址取得指定的视频缩略图
* @param cr ?
* @param uri ?本地视频Uri标示
* @return 返回bitmap类型数据
*/
public static Bitmap getVideoThumbnail(ContentResolver cr, Uri uri) {
Bitmap bitmap = null;BitmapFactory.Options options = new BitmapFactory.Options();options.inDither = false;options.inPreferredConfig = Bitmap.Config.ARGB_8888;Cursor cursor = cr.query(uri,new String[] { MediaStore.Video.Media._ID }, null, null, null); if (cursor == null || cursor.getCount() == 0) { return null;}cursor.moveToFirst();String videoId = cursor.getString(cursor.getColumnIndex(MediaStore.Video.Media._ID)); //image id in image table.sif (videoId == null) {return null;}cursor.close();long videoIdLong = Long.parseLong(videoId);bitmap = MediaStore.Video.Thumbnails.getThumbnail(cr, videoIdLong,Images.Thumbnails.MICRO_KIND, options);return bitmap;}?/**
* 根据视频在手机中的地址路径取得指定的视频缩略图
* @param cr ?
* @param fileName ?本地视频地址
* @return 返回bitmap类型数据
*/
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public static Bitmap getVideoThumbnail(ContentResolver cr, Uri uri) {Bitmap bitmap = null;BitmapFactory.Options options = new BitmapFactory.Options();options.inDither = false;options.inPreferredConfig = Bitmap.Config.ARGB_8888;Cursor cursor = cr.query(uri,new String[] { MediaStore.Video.Media._ID }, null, null, null); if (cursor == null || cursor.getCount() == 0) { return null;}cursor.moveToFirst();String videoId = cursor.getString(cursor.getColumnIndex(MediaStore.Video.Media._ID)); //image id in image table.sif (videoId == null) {return null;}cursor.close();long videoIdLong = Long.parseLong(videoId);bitmap = MediaStore.Video.Thumbnails.getThumbnail(cr, videoIdLong,Images.Thumbnails.MICRO_KIND, options);return bitmap;} 
