flutter - Flutter TfLite 模型在每次热重载后仅发送一次输出，有时也是随机的

Question

我一直在尝试运行一个对不同食品进行分类的模型。该模型运行一次，但当我再次尝试时，它给出了错误。我之前曾在另一个有动画按钮的应用程序上尝试过 tflite，我只为按钮设置了动画控制器，并且该应用程序仍然有效，我无法找到我错的地方。

import 'dart:io';
import 'package:tflite/tflite.dart';

import 'package:flutter/material.dart';
import 'package:flutter_fashion/Constants/text_styles.dart';
import 'package:image_picker/image_picker.dart';

class HomeTab extends StatefulWidget {
  const HomeTab({Key? key}) : super(key: key);

  @override
  _HomeTabState createState() => _HomeTabState();
}

class _HomeTabState extends State<HomeTab> {
  bool _loading = true;
  late File _image;
  late List _output;
  final picker = ImagePicker();

  @override
  void initState() {
    super.initState();
    loadModel().then((value) {
      setState(() {});
    });
  }

  @override
  void dispose() {
    super.dispose();
    Tflite.close();
  }

  classifyImage(File image) async {
    //this function runs the model on the image
    var output = await Tflite.runModelOnImage(
      path: image.path,
      numResults: 36, //the amount of categories our neural network can predict
      threshold: 0.5,
      imageMean: 127.5,
      imageStd: 127.5,
    );
    setState(() {
      _output = output!;
      _loading = false;
    });
  }

  loadModel() async {
    //this function loads our model
    await Tflite.loadModel(
        model: 'assets/model.tflite', labels: 'assets/labels.txt');
  }

  pickImage() async {
    //this function to grab the image from camera
    var image = await picker.getImage(source: ImageSource.camera);
    setState(() {
      if (image != null) {
        _image = File(image.path);
      } else {
        print('No image selected.');
      }
    });
    classifyImage(_image);
  }

  pickGalleryImage() async {
    //this function to grab the image from gallery
    var image = await picker.getImage(source: ImageSource.gallery);
    setState(() {
      if (image != null) {
        _image = File(image.path);
      } else {
        print('No image selected.');
      }
    });
    classifyImage(_image);
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: EdgeInsets.symmetric(horizontal: 10, vertical: 10),
      child: Container(
        alignment: Alignment.center,
        decoration: BoxDecoration(
          color: Color(0xFFFFFFFF),
        ),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Container(
              child: Center(
                child: _loading == true
                    ? null //show nothing if no picture selected
                    : Container(
                        child: Column(
                          children: [
                            Container(
                              height: 250,
                              width: 250,
                              child: ClipRRect(
                                borderRadius: BorderRadius.circular(30),
                                child: Image.file(
                                  _image,
                                  fit: BoxFit.fill,
                                ),
                              ),
                            ),
                            SizedBox(
                              height: 25,
                            ),
                            if (_output == null)
                              Container()
                            else
                              Text(
                                '${_output[0]['label']}',
                                style: Constants.regularDarkText,
                              ),
                            SizedBox(
                              height: 25,
                            ),
                          ],
                        ),
                      ),
              ),
            ),
            Container(
              child: Column(
                children: [
                  GestureDetector(
                    onTap: pickImage,
                    child: Container(
                      width: MediaQuery.of(context).size.width - 200,
                      alignment: Alignment.center,
                      padding:
                          EdgeInsets.symmetric(horizontal: 24, vertical: 17),
                      decoration: BoxDecoration(
                          color: Colors.black,
                          borderRadius: BorderRadius.circular(15)),
                      child: Text(
                        'Take A Photo',
                        style: TextStyle(
                          fontFamily: "FiraSansCondensed",
                          fontSize: 18.0,
                          color: Colors.white,
                          fontWeight: FontWeight.w600,
                        ),
                      ),
                    ),
                  ),
                  SizedBox(
                    height: 30,
                  ),
                  GestureDetector(
                    onTap: pickGalleryImage,
                    child: Container(
                      width: MediaQuery.of(context).size.width - 200,
                      alignment: Alignment.center,
                      padding:
                          EdgeInsets.symmetric(horizontal: 24, vertical: 17),
                      decoration: BoxDecoration(
                          color: Colors.black,
                          borderRadius: BorderRadius.circular(15)),
                      child: Text(
                        'Pick From Gallery',
                        style: TextStyle(fontFamily: "FiraSansCondensed",
                          fontSize: 18.0,
                          color: Colors.white,
                          fontWeight: FontWeight.w600,),
                      ),
                    ),
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }
}

错误：

======== Exception caught by widgets library =======================================================
The following RangeError was thrown building HomeTab(dirty, dependencies: [MediaQuery], state: _HomeTabState#f9e09):
RangeError (index): Invalid value: Valid value range is empty: 0

The relevant error-causing widget was: 
  HomeTab file:///D:/Programming/Flutter/Flutter%20Fashion/flutter_fashion/lib/Views/home_page.dart:46:19

标签： fluttertensorflowdartmachine-learningtensorflow-lite