clear method
void
clear()
Implementation
void clear() async {
var list = _updateList();
mmkv.remove(dfKey);
for (var item in list) {
try {
if (!item.dcFile.isNullOrEmpty) await File("$savePath${item.dcFile}").delete();
} catch (e) {
print("$e");
}
item.dcDel;
}
}