文件大小转换工具Formatter.formatFileSize(MainActivity.this, bitmap.getByteCount())

------ 文件大小转换工具

Formatter.formatFileSize(MainActivity.this, bitmap.getByteCount())

① 将字节byte转化为以B（字节）、KB、MB等为单位的数值，

  Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.icon, null);
                Log.i(tag, "run: 原始bitmap filesize = " + Formatter.formatFileSize(MainActivity.this, bitmap.getByteCount()));

                BitmapFactory.Options options = new BitmapFactory.Options();
                options.inSampleSize = 30;

                final Bitmap bitmap1 = BitmapFactory.decodeResource(getResources(), R.drawable.icon, options);
                String formatFileSize1 = Formatter.formatFileSize(MainActivity.this, bitmap1.getByteCount());
                Log.i(tag, "run:  options.inSampleSize = 1000 filesize = " + formatFileSize1);

04-01 01:44:34.640 2094-2107/? I/filesize: run: 原始bitmap filesize = 184KB

04-01 02:23:26.090 7052-7072/com.adnonstop.gaussianbg I/filesize: run:  options.inSampleSize = 30 filesize = 144B

② Formatter.formatFileSize会根据文件字节数转化为合适的单位（B、KB、MB等数值）数值。