尝试使用firebase_ml_vision

Question

我正在尝试使用firebase_ml_vision从图像读取文本。我得到了图像，但是当我尝试获取文本时，出现了错误：“默认FirebaseApp在此过程com.example.flutter_tfg中未初始化。请确保先调用FirebaseApp.initializeApp（Context）。”

我已将依赖项firebase_ml_vision：^ 0.7.0添加到pubspec.yaml。

我的应用失败的代码是：

File pickedImage;

  bool isImageLoaded = false;

  Future pickImage() async {
    var tempStore = await ImagePicker.pickImage(source: ImageSource.gallery);

    setState(() {
      pickedImage = tempStore;
      isImageLoaded = true;
    });
  }

  Future readText() async {

    FirebaseVisionImage ourImage = FirebaseVisionImage.fromFile(pickedImage);
    TextRecognizer recognizeText = FirebaseVision.instance.textRecognizer();
    VisionText readText = await recognizeText.processImage(ourImage);

    for (TextBlock block in readText.blocks) {
      for (TextLine line in block.lines) {
        for (TextElement word in line.elements) {
          print(word.text);
        }
      }
    }
  }

我在做什么错了？