当用户脱机时，如何在Flatter中向firebase添加/上载数据时显示错误？

基本上，当用户尝试添加文档或将图像上载到firestore cloud/firebase存储时，我尝试显示一个警报对话框。我用try-and-catch块以及.catchError（）尝试了这个方法，但它不起作用，基本上是在连接到internet后进行的。我想做的是显示一个警报对话框并取消该过程，即使用户恢复了连接（他必须再次重复上传过程）。以下是我的代码示例：

这用于拾取和上载图像：

 Future _getImage(bool isCamera) async {
    var pickedImage;
    try {
      if (isCamera)
        pickedImage =
            await picker.getImage(source: ImageSource.camera, imageQuality: 20);
      else
        pickedImage = await picker.getImage(
            source: ImageSource.gallery, imageQuality: 20);

      if (pickedImage != null) {
        _uploadAndSetUrl(File(pickedImage.path));
      }
    } catch (e) {
      print('error here');
    }
  }

  Future _uploadAndSetUrl(File image) async {
    try {
      _uploadingStatus(true);
      StorageUploadTask uploadTask = _bookImageRef.putFile(image);
      StorageTaskSnapshot taskSnapshot = await uploadTask.onComplete;
      String downloadAddress = await _bookImageRef.getDownloadURL();
      _uploadingStatus(false);
      setState(() {
        _imageUrl = downloadAddress;
      });
      print(_imageUrl);
    } on PlatformException catch (e) {
      print('error: $e');
    } catch (e) {
      print('No image added');
    }
  }

还有另一种方法可以将文档添加到firestore云中。有办法吗

提前谢谢你

试试这个

import 'dart:io';

Future _getImage(bool isCamera) async {
    var pickedImage;
    try {
      if (isCamera)
        pickedImage =
            await picker.getImage(source: ImageSource.camera, imageQuality: 20);
      else
        pickedImage = await picker.getImage(
            source: ImageSource.gallery, imageQuality: 20);

      if (pickedImage != null) {
      try {
        final result = await InternetAddress.lookup('google.com');
      if (result.isNotEmpty && result[0].rawAddress.isNotEmpty) 
        _uploadAndSetUrl(File(pickedImage.path));
       
    } on SocketException catch (_) {
    showDialog(
          context: context,
          builder: (context) => AlertDialog(
            title: Text("Connection Error !"),
            content: Text("Please connect to the internet."),
          )
      );
 }
        
      }
    } catch (e) {
      print('error here');
    }
  }

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如果有帮助，请告诉我