I am getting the following error while expecting the method buildSplashScreen() to return image:

D/MediaScannerConnection(10257): Scanned /storage/emulated/0/Android/data/com.fluttershare.fluutershare/files/Pictures/e1c7909c-9c92-42c1-a7b4-1155b56931267294677592146716356.jpg to null
════════ Exception caught by widgets library ═══════════════════════════════════ The following assertion was thrown building Upload(dirty, dependencies: [_LocalizationsScope-[GlobalKey#50363]], state: _UploadState#dc89a): A build function returned null. >

This is my code below:

import 'package:flutter/material.dart';
import 'package:flutter_svg/flutter_svg.dart';
import 'package:image_picker/image_picker.dart';

class Upload extends StatefulWidget {
  @override
  _UploadState createState() => _UploadState();
}

class _UploadState extends State<Upload> {
  final ImagePicker _picker = ImagePicker();

  PickedFile file;

  handleTakePhoto() async {
    Navigator.pop(context);
    PickedFile file = await _picker.getImage(
        source: ImageSource.camera, maxHeight: 675, maxWidth: 900);
    setState(() {
      this.file = file;
    });
    return file;
  }

  handleChooseFromGallery() async {
    Navigator.pop(context);
    file = await _picker.getImage(source: ImageSource.gallery);
    setState(() {
      this.file = file;
    });
    return file;
  }

  selectImage(parentContext) {
    return showDialog(
        context: parentContext,
        builder: (context) {
          return SimpleDialog(
            title: Text('Create Post'),
            children: <Widget>[
              SimpleDialogOption(
                child: Text('Photo with Camera'),
                onPressed: handleTakePhoto,
              ),
              SimpleDialogOption(
                child: Text('Photo from Gallery'),
                onPressed: handleChooseFromGallery,
              ),
              SimpleDialogOption(
                child: Text('Cancel'),
                onPressed: () => Navigator.pop(context),
              ),
            ],
          );
        });
  }

  Container buildSplashScreen() {
    return Container(
      color: Colors.indigo,
      child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            SvgPicture.asset(
              'assets/images/upload.svg',
              height: 260.0,
            ),
            Padding(
              padding: EdgeInsets.only(top: 20.0),
              child: ElevatedButton(
                  child: Text(
                    "Upload Imgae",
                    style: TextStyle(
                      color: Colors.white,
                      fontSize: 20.0,
                    ),
                  ),
                  onPressed: () => selectImage(context)),
            ),
          ]),
    );
  }

  buildUploadForm() {
    Text('File loaded');
  }

  @override
  Widget build(BuildContext context) {
    return file == null ? buildSplashScreen() : buildUploadForm();
  }
}

CodePudding user response：

Add return to buildUploadForm method:

Widget  buildUploadForm() {
   return Text('File loaded');
  }