Future getImage() async {
var image = await ImagePicker.pickImage(source: ImageSource.camera);
setState(() {
_image = image;
print("IMG:" + _image.toString());
});
setPrefs() ;
}
Future setPrefs() async {
_base64 = base64.encode(_image.readAsBytesSync());
print(_base64);
final prefs = await SharedPreferences.getInstance();
prefs.setString(IMAGE_KEY, _base64);
}
readAsBytesSync（）方法在Android上运行良好，但在iOS中运行速度太慢 . 那么如何将此代码移动到新的后台线程？