getFileBytes function
判断是否有对应图片缓存文件存在
Implementation
Future<Uint8List?> getFileBytes(String url) async {
String cacheDirPath = await getCachePath();
String urlMd5 = getUrlMd5(url);
// return await compute(_getFileBytes,"$cacheDirPath/$urlMd5");
File file = File("$cacheDirPath/$urlMd5");
try{
return await file.readAsBytes();
}catch(e){
//ignore
}
return null;
}