readBinaryFile method
Reads a binary file from assets folder.
Implementation
Future<Uint8List> readBinaryFile(String fileName, {String? package}) async {
final cacheKey = package == null ? fileName : 'packages/$package/$fileName';
if (!_files.containsKey(cacheKey)) {
_files[cacheKey] = await _readBinary(fileName, package: package);
}
assert(
_files[cacheKey] is _BinaryAsset,
'"$cacheKey" was previously loaded as a text file',
);
return (_files[cacheKey]! as _BinaryAsset).value;
}