Flutter : I have NULL in my variable , How to use my function?

Question

class _ProfilePageState extends State<ProfilePage> {
  String tmpimage;

  Uint8List TmpBytesImage;
  File pimage;

  void initState() {
    super.initState();
    Future.delayed(Duration.zero, () {
      TmpBytesImage= profileimage();
    });
  }

  profileimage() async {
    var userimage1 = await DBHelper().getuserIMAGE1('roro');
    print(userimage1);
    if (userimage1 == Null) {
      print('Empty');
    } else {
      setState(() {
        userimage1.map((e) {
          tmpimage = e['image0'];
        }).toList();
        print(tmpimage);
        return Base64Decoder().convert(tmpimage);
      });
    }
  }

The first error was:

Only static members can be accessed in initializers

I added :

void initState() {
    super.initState();
    Future.delayed(Duration.zero, () {
      TmpBytesImage= profileimage();
    });
  }

Then it seemed to be working normally.

But there is a null value in the TmpBytesImage. How to fix it?

CopsOnRoad · Accepted Answer · 2019-10-12 14:45:03Z

1

That's because you were not awaiting on your future method. Just replace your initState with this:

void initState() {
  super.initState();
  Future.delayed(Duration.zero, () async{
    TmpBytesImage = await profileimage();
  });
}

answered Oct 12, 2019 at 14:45

CopsOnRoad

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5 Comments

killer whale Over a year ago

still Null,,,,,

CopsOnRoad Over a year ago

Can you tell me what print(userimage1); is printing on console?

killer whale Over a year ago

when I use print(userimage1);, it's NULL on the console.

CopsOnRoad Over a year ago

Which actually means there is something your database returns you null, and you return this null to your TmpBytesImage, so there is no problem in above solution, all you need to do is debug your app and check why database is returning null for roro

killer whale Over a year ago

In the profileimage() , it contains values, but onTap:() print(userimage1); is not contained in it.

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