public Bitmap decodebitmap(Context context, int imageid) {BitmapFactory.Options options = new BitmapFactory.Options();options.inJustDecodeBounds = true;// 如果值设为true，那么将不返回实际的bitmap，也不给其分配内存空间，这样就避免了内存溢出。Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(),imageid, options);if (bitmap == null) {Toast.makeText(context, "bitmap为空", 2).show();//这里能出来，是因为options.inJustDecodeBounds = true;}int realwidth = options.outWidth;int realheight = options.outHeight;System.out.println("图片真实高度" + realheight + "宽度" + realwidth);// 计算缩放。int scal = (int) ((realheight > realwidth ? realwidth : realheight) / 100);if (scal <= 0) {scal = 1;}options.inSampleSize = scal;options.inJustDecodeBounds = false;bitmap = BitmapFactory.decodeResource(context.getResources(), imageid,op